Colour mixing: clarifications

Recently I was asked if I could post the five colour mixing chapters from my book “Painting with Light and Colour” (Chapters 11 – 15).  I will be surprised if you do not find that many of the ideas in them are new, interesting and practical. At the bottom of the page is a link  to Chapter Eleven, the first of the four chapters, whose title is, “Colour mixing – definitions and misconceptions”. To whet your appetite (below the image) I have included a slightly edited version of its “Introductory”.

Coloour mixing 1
Figure 1 – A young student exploring some of  the practical colour mixing ideas explained in the four colour-mixing chapters of my book

Introductory to Chapter Eleven

At the outset of my life as an artist, my conception of colour-mixing was of a dry and mechanical subject. I thought of it as no more than one of those necessary basic skills that could easily be picked up along the road. To my surprise, nothing turned out to be quite so routine as it had seemed, and one line of enquiry led to another in a most seductive way. Each new development plunged me deeper into the history either of science or of art, until an engagingly coherent story emerged. The result was a practical understanding of a kind that might be difficult to find elsewhere.

“Most how-to-do-it art books have sections on colour-mixing and there are a number of tomes that offer technical information for professionals.  These latter tell us that scientists have understood the physics underpinning colour-mixing theory for a very long time: Certainly they have done so since James Clerk Maxwell’s lecture on colour vision, given at the Royal Institute, two years before the First Impressionist Exhibition in 1874.

In view of the availability of all these  sources of information, it might be thought that there is nothing left to add. Unfortunately, this is far from the case. The problem is that:

  • Too many painters are being seriously misled by the half-truths and even falsehoods which have entered into the stock in trade of popular colour-mixing theory.
    Science has far from stood still since the 1870s.
  • Particularly since the 1970s, scientists have been finding out a great deal of new information about how eyes and brains work and, as a result, have arrived at a number of new understandings that could help artists in practical ways, which are not being made use of by the artistic community.

For these reasons and others, it is clear to me that there is a need for the up-to-date approach to practical colour mixing that is supplied by the next chapters.

One approach to clarifying matters is to place the information presented in an historical context. Doing so reveals that:

  • Some of the best of ideas have been obscured by the passage of time.
  • The evolution of colour-mixing theory, owes much to parallel development of the histories of science and of art.
  • The story of when, how and why artists adopted new colour-mixing practices, provides many insights into their potential uses in painting.

With respect to the links between the discoveries of the scientists of visual perception and the practice of the artists, the evidence is usually sparse and often ambiguous. To compound the problem history (not least the history of science) becomes distorted because it is told by people who write with the benefit of hindsight and sometimes from the perspective of a particular prejudice.

It may surprise some people to find how many famous scientists are credited both with more originality and much more fully developed and rounded versions of their ideas than they actually had. A mismatch of this kind may be suspected in the relation between the confusions inherent in the early development of the ideas developed by Seurat and Cézanne and the neat synthesis of them by Professor Bohusz-Szyszko. Similarly it is unlikely that any of the early Impressionists had as clear a conceptual framework concerning the real surface/illusory space dynamic as was eventually to evolve from their pioneering ideas. While these are very interesting areas for discussion, the process of trying to unearth and pin down exactly what the early pioneers had in mind is a work for scholars. The focus of this book is artistic practice and it is the more refined picture as developed by the more recent artists and theorists that are the most useful in terms of their practical value.

We start a short survey of these by providing some basic definitions as used in this book:


CHAPTER ELEVEN – Colour mixing – Definitions and misconceptions

Other Chapters from “Painting with Light and Colour”.

Other Posts on colour and light in painting:

Chapters from “What Scientists can Learn from Artists”

These deal in greater depth with subjects that feature in the other volumes

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Aerial perspective: Theory & warnings

Today, I have been editing the entry for aerial perspective in the Glossary for my books. As I was making my corrections, I had the idea that readers of the Posts Page of this website might like a preview of this and future Glossary edits that I feel might interest them. So, to start the ball rolling, here is a slightly expanded version of the one on aerial perspective, with four images added.

Aerial perspective: Between any viewer and the surfaces of the objects at which they are looking lies a portion of the earth’s atmosphere. In addition to the transparent gases that make up air, this contains quantities of dust and other particulate matter (such as the water droplets in mist and, more evidently nowadays, various kinds of pollution). The effect of the intervening atmosphere on the appearance of distant hills and objects seen is well known to us all. We all perceive distant parts of landscapes being bluer and/or greyer  and lighter than nearer parts, and objects seen through mist or fog appear progressively greyer and lighter as the distance between them and us increases. Many artists dating back to the Italian Renaissance, most famously Leonardo da Vinci (1452 – 1519) and Claude Lorrain (1600 – 1682), have demonstrated the value of applying these principles in paintings. So convincing was their effect, that they were adopted as “rules”  by the French  Académie Royale de Peinture et de Sculpture soon after it was founded in the mid seventeenth century.  No one would dispute that the images in Figure 1 and Figure 2 produce a sense of progressive distance.


Aerial perspective
Figure 1 : Leonardo da Vinci – detail of “the Virgin of the Rocks”


Aerial perspective
Figure 2 : Claude of Lorrain- Classical landscape



  • Although the theory explaining aerial perspective is scientifically sound and although it virtually always has an important effect on how we perceive both distant parts of landscapes and objects on misty days, it has no discernible effect on how we perceive objects within an arms length. So at what distance does its influence become apparent? The answer is that it varies according to the composition and density of the particles floating about within it.  Thus, on dry, bright days of the kind that often follow abundant heavy rain, when the air has been washed clean, the visibility of atmospheric intervention is minimised, whereas on a hot sultry or misty days, when the air is at its fullest of dust and pollution, it is maximised. In practice, this can mean that on a clear day its effect on the appearance of objects hundreds of meters away may not be discernible.
  • Despite these facts of appearances, over the years, I have found that many students, when they first come to my Painting School, have been in the habit of adding blue to objects much nearer than that (in one exceptional case, a newcomer, when painting a bunch of flowers in a vase, added blue to the colour of flowers and foliage at the back of the arrangement, arguing that it made it look further away). When I see this being done, it tells me is that the student in question cannot have been looking at the near/far colour/lightness relativities. If so, how can they appreciate the amazing riches of colour relations in nature? They need to learn that rules are not for following blindly, but for testing, a process which will always open doors of awareness.
  • To further complicate the situation, there are a number of other variables that can result in people perceiving more distant surfaces of a particular colour as brighter and more fully saturated than nearer surfaces of the same colour: In other words, the opposite of the aerial perspective rule. For example, in summertime, the green canopies of distant oak trees that are illuminated by bright sunlight will look lighter and brighter than those of nearer oak trees should they happen to be situated in the shadow of clouds. Also, a boat on a lake that is painted with a fully saturated red that is actually further away from the viewer than a boat painted with a desaturated red will still look further away. If we made a painting of them, matching as best as possible the colours as we see them, the laws of aerial perspective would predict that the further boats would be perceived as being nearer than the nearer boat. Clearly there needs to be a way of depicting distance that has nothing to do with the representation of atmospheric intervention. Luckily there are several of these, including overlap, relative size and texture cues, but only one of them necessitates the use of colour. Unfortunately, this colour-dependent way of enhancing illusory pictorial space appears to be little known, despite its solid foundations in well known history, its sound scientific underpinning and the ease of its practical application. Much of my book “Painting with Light and Colour” is devoted to giving it new life. If you want to know more, read chapters already published on this website and watch for later Posts.

Two examples of minimal effect of aerial perspective, containing contradictions to the laws as exemplified by Clause Lorrain.

John Constable (1776 – 1837) was a great admirer of Claude Lorrain, but he looked more carefully at nature. Figure 3 and Figure 4 are images of two of his paintings that contain elements that are not consistent with a rigorous interpretation of the laws of aerial perspective. See how many you can find?


aerial perspective
Figure 3 : John Constable, – “Flatford Mill”.


aerial perspective
Figure 4 : John Constable “Wivenhoe Park”.


Now look at paintings by the Impressionists – Monet, Renoir Pissaro, Cezanne, Gauguin, Bonnard, etc. – to see how much they make use of the rules of aerial perspective. Where they do make use of them, was this the result of applying the rules or of looking carefully at nature? According to what is written above, far distant hills should always actually look bluer or greyer, but what about landscapes representing the kind of distances depicted by Constable or shorter ones?

Effect of patchy cloud cover on relative brightnessess

Finally to ram the point home, here are three photographs that illustrate how patchy cloud cover can produce contradictions to the laws of aerial perspective.


aerial perspective
Figure 5 : Duller nearer/brighter further


Figure 5  illustrates an exception to the law. Due to their being brightly illuminated by sunlight, the walls of the distant church tower are much brighter than those of the house in the foreground, which is in the shadow of passing clouds.


aerial perspective
Figure 6 : Brighter nearer/duller further


In Figure 6 the situation is reversed. The walls of the house in the foreground are now brightly illuminated by direct sunlight and are much brighter than those of the church tower, which is now in the shadow of passing clouds.

Figure 7 shows:

  • The far house,
  • The strip of green field in front of it,
  • The sunlit patches of brown earth in the ploughed field,

as being brighter than,

  • The near house,
  • The ribbon of green field in the bottom left of the image,
  • The area of brown earth immediately above it.


aerial perspective
Figure 7 : Duller nearer/brighter further


In all three images atmospheric intervention is playing a part, but in Figure 5 and Figure 7, its effects are being obscured in the ways described.





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Painting space with colour

The new science

The purpose of this Post is  to provide a link to Chapter 10 “Illusory pictorial space and  light”,  from my book, “Painting with Light and Colour”. This provides a simplified explanation of the science behind the ideas developed in earlier chapters concerning ways of creating and/or enhancing effects of illusory pictorial space by means of using mixtures containing small proportions of complementary colours. In the process it explains why the same method can be used to create harmony in paintings. It also explains why colour repetition has the potential, not only to produce visual discord, but also to generate optical excitements.




Examples of painting space and creating harmony with colour

painting space
Paul Cézanne: Still life, provides and example of how making a painting that fits into the rules of Professor Bouhusz-Szyszko creates  a sense of space, light and harmony.


painting space
Pierre Bonnard : Landscape, provides a second example of how making a painting that fits into the rules of Professor Bouhusz-Szyszko creates  a sense of space, light and harmony.


Examples of repeated colours without mixtures of complementaries


painting space
Francis Bacon : On of his Pope paintings, in which repeated colours, whether intentionally or not, enhance shock value



painting space
Jackson Pollock : Echo No 23 (detail) -The influential critic Clement Greenberg admired Pollock for creating a “space within the picture surface”.



painting space
Victor Vassarely : Op Art – used lstrong cognitive cues and many repeating colours to create a powerful visual impact.


Other chapters from “Painting with Light and Colour”:

Other Posts on colour and light in painting:

Chapters from “What Scientists can Learn from Artists” that go more deeply into  some of the subjects referred in the Posts above


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Vision Group acknowledged

Members of the University of Stirling Vision Group

In many places in my books, I acknowledge the importance of the role of colleagues from University of Stirling in the development of the new science-based ideas put forward in them. In particular I mention cooperations with scientists from various departments who later were to join me in the University of Stirling Vision Group. The most important of these were:

  • Alistair Watson (Physics, psychology and computer imagery).
  • Leslie Smith * (computing).
  • Bill Phillips * (visual memory and brain function).
  • Karel Gisbers (neurophysiology).
  • Ranald McDonald (statistics and common sense).
  • Lindsay Wilson * (at the time working on aspects of visual perception).

Also, although Peter Brophy * did not join our group, he was an ever-available and important source of information on the biochemistry of the brain.

The founding of the Vision Group.

It was in  the Autumn of 1984 that Alistair, Leslie and I took the first steps in the setting up of the University of Stirling Vision Group, which was to have many meetings attended by the above named colleagues and other members of the various interested Departments. Its starting point was a package of ideas developed by Alistair and myself, and two core algorithms based on them, produced by Alistair.  These were:

  • A colour constancy algorithm, capable of modelling both spatial and temporal colour constancy, which was inspired by our interpretation of how this phenomenon is achieved by human eye/brain systems. As a preliminary step to achieving this main objective, the algorithm has to pick off the information about surface-reflection. Since it was obvious that the reflected-light contained information, we speculated upon how it might be used by the eye/brain. Due to my interest in picture perception, we focused on its potential for computing surface-form, in front/behind relations, and the wavelength composition of ambient illumination.**
  • A “classification/recognition algorithm”, based on our interpretation of how human eye/brain systems achieves their primary task of enabling recognition.***

We could not help being excited by the early tests of these algorithms and the speculations concerning their potential. In our  enthusiasm to push matters further, Alistair suggested we should seek the help of other researchers, particularly ones with expertise in:

  • Mathematics and computing.
  • Visual perception with special reference of visual memory.

It was at this juncture that, having decided on a name for what we were hoping would become a collaborative group, we contacted Leslie Smith for his mathematical and computing skills. But this was only a start. Once Leslie was on board, we approached Bill Phillips, whose long standing interest in visual memory had led him to take the plunge into the recently emerging domain of neural networks and learning algorithms. After many Vision Group meetings, much sharing of ideas, many hours spent working on implementations of algorithms, and the writing of a number of working papers, we decided to submit a suite of five grant applications to the Science and Engineering Research Council, who had let it be known that they were looking for groups of researchers working on the use of computers to model the functional principles of neural system. The stated aim of the SERC was to set up a small number of “Centres of Excellence” in this domain.  Not only were two of our grant applications accepted (one submitted by Bill Phillips and one submitted by Leslie Smith), but also our university was encouraged to create a brand new  Centre for Cognitive and Computational Neuroscience . This empire absorbed the University of Stirling Vision Group which ceased to have an independent existence. Its coming into existence also coincided with my departure from Stirling on my way to founding my Painting School of Montmiral, where I intended to put theory into practice both in my own work and in my teaching. I also had hopes of confirming and, with any luck, extending the theory. Also after leaving Stirling University, Alistair and I were founder members of a small software development company which used ideas developed within the Vision Group as a basis for creating an image manipulation tool. ****


* The links to Bill, Leslie, Lindsay and Peter relate to their current status. Alistair, Karel and Ranald all retired or died before the Internet became the essential information source it has since become.

** My book is full of examples of how fruitful this speculation proved to be.

*** In 1987 Alistair published:  “a new method of classification” in Pattern Recognition Letters, Volume 6, Issue 1, June 1987, Pages 15-19

****  Fluid Mask: a commercial outcome

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Can we see light?

The simple answer is “no”

What we see is not light, but experiences created by neural networks within the eye and the brain (what I often refer to as “eye/brain systems”). Although it is true that the visual world that we know could not happen in the absence of the patterns of light that enter our eyes, it is only made manifest to us as a result of what is going on inside our heads.  This Post provides a link to Chapter 9 of my book “Painting with Light and Colour”, which describes two demonstrations that show just how great can be the difference between an image predicted on the basis of readings from a light meter and the one we actually experience.

Edwin Land’s demonstrations

The demonstrations have a personal importance because they played a key role in the story of my quest to explain the paradox inherent in the dogmas of Marian Bohusz-Szyszko  (explained in Chapter 2). They were devised by Edwin Land, the famous inventor, as a part of his investigation of the phenomenon of “colour constancy”.


More on Land’s demonstration

For another relevant source of information on Land’s demonstration please consult “Land’s colour constancy demonstration”, an edited version of a chapter from my book “What Scientists can Learn from Artists”. You might also want to read the original article in  “Scientific American, December 1977”.  In this Land explained what he described as his “Retinex theory of colour vision”.

The multicoloured display used by Land as the cover for his 1977  article in the “Scientific American”


Other chapters from “Painting with Light and Colour”:


Other Posts on colour and light in painting:


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Seurat’s new idea

“Painting with light”:

The main purpose of this Post is to explain what I mean by “Seurat’s new idea”. Most people would probably leap to the conclusion that I am referring to the “Pointillist method” that he developed, and for which he is justly renowned. But the method was never the main idea, which was to “paint with light” (as opposed to merely “painting light”). No previous artist had attempted to do this.

At least since the Italian Renaissance, the artistic community had been particularly interested in depicting effects of natural or artificial light on the appearance of objects and scenes.  They made impressive progress by conceiving matters in terms of  whole-field lightness relations (chiaroscuro). Seurat’s new idea opened up the unexplored possibility of introducing the dimension of colour into the mix. In doing so, whether directly or indirectly, he was responsible for opening the way for the possibility of adding a new dimension to the experience provided by representations of the effects of light in paintings.

In itself, this step could justifiably be described as a “quantum leap”, but as it turned out the influence of Seurat’s new idea was to have other far reaching implications. In time it would also lay the foundations  for enhancing, not only effects of “illusory pictorial space” but also the sense of both “surface” and “surfacelessness” in paintings.

But even this was not all, for another side-effect of Seurat’s new idea was its contribution to the explosion of colourfulness in paintings.  This had been kick started by the discovery by scientists that colour is not a property of surfaces in the external world, but a creation of  eye/brain systems. In the wake of this mind blowing reality, earlier Modernist artists were already using brighter colours and juxtaposing complementary pairs, but two requirements of the Pointillist method pushed matters significantly further. These were:

  • The systematic use of  juxtaposed complementary colour pairs, within the optically mixed arrays of tiny dots that characterise Pointillism.
  • The need to conceive of colour mixing in terms of a colour circle with many more segments than the six segment one (consisting of three primaries and their three complementaries) favoured by the Impressionists. Seurat’s idea meant that he had to represent as many parts of the visible spectrum as possible. To do this he needed to make use of the widest range of the most fully saturated pigment colours available.

Between them these innovations had the effect of hugely increasing the range and subtlety of both colours and colour combinations  to be found in paintings produced after 1886, the year that Seurat first exhibited “La Grande Jatte”, his game-changing painting.

For more details click on the link below to Chapter 8 of my book “Painting with Light and Colour”. For those who have not read the previous four chapters, the next section provides a short resume of them (links to the chapters themselves can be found at the bottom of this page).

Short resume of previous chapters

  • Chapter 4 : Describes the Renaissance approach to painting light, which centred on local and whole-field lightness relations with particular reference to finding the darkest and lightest regions in the scene (chiaroscuro) and gradations of lightness across surfaces. In this scheme of things the depiction of shadows was a matter of painting “what you see”, which seemed reasonable enough, but brought with it all sorts of unsuspected problems.
  • Chapter 5 : Focuses on the scientific revolution in the understanding of light and colour that had its origins in the work of Isaac Newton and the insights of the numerous scientists who realised that all sensory experiences including those that relate to colour and effects of light are made in the head. Newton clarified the physical nature of light. The perceptual scientists introduced concepts like the“three primaries”, “induced colour”, “complementary colours” and “colour/lightness contrast effects”.
  • Chapter 6 : Shows that the Impressionists had an agenda which included the idea of emphasising the reality of the picture surface and playing off the ephemeral and the permanent aspects of appearance.
  • Chapter 7 : Uses photographs to elucidate the meaning of the words “opaque”, “translucent”, “glossy” and “matt”. Particular attention is given to effects on appearances of interreflections and viewing angles.

The diagrammatic origin of Seurat’s new idea

As it does not appear in Chapter 8, but earlier in the book, I am including in this Post the diagram from a physics book that kick started Seurat’s new idea. It was from this that he learnt that  the white daylight light that strikes a surface interacts with it in one of two ways:

  • One part enters the surface and is scattered around inside, before being scattered back out again. While inside, some wavelengths are absorbed. The remainder are scattered-back-out again to produce the limited wavelength combinations that give us “body colour”.
  • The remainder never enters the surface, but is reflected back directly from it (as from a mirror), such that it leaves it without changing its wavelength composition to produce “reflected light”.

The component that interested Seurat is the “reflected light”. By combining his understanding of this with the discoveries of perceptual scientists mentioned above, Seurat believed that he could represent it in paintings by means of mosaics of tiny dots containing juxtapositions of complementary, or near-complementary, pairs.




The inspirational diagram

Seurat's new idea
The diagram that seeded Seurat’s new idea. It is the reflected back “white” light that informs the eye/brain about surface-solidity, surface-form, in front/behind relations and ambient illumination.


Posts relating to other chapters from “Painting with Light and Colour”:

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Reflected light and surface perception

Subtleties of reflected light

The purpose of this Post is to provide the link below to “The perception of surface”, Chapter 7 of my book “Painting with Light and Colour”. This provides illustrations and explanations of ways we perceive: (a) reflected light as opposed to transmitted light, (b) matt surfaces as opposed to glossy ones, and (c) the complexities of interreflections. Apart from their intrinsic interest, the function of these in the book is to prepare the ground for the next chapters, which explain how Georges Seurat’s ideas about “painting with light”, either directly or, more often, indirectly, were to revolutionise the use of colour in paintings in a multiplicity of ways. Thus, the next Post will provide a link to Chapter 8, which, after introducing Seurat’s ideas and methods, starts the process of going more deeply into their game-changing ramifications. What follows below gives a foretaste of the nature of these.

Game-changing ramifications

Not nearly enough importance is given to the impact of Georges Seurat’s ideas concerning the depiction of reflected light. Their significance lies in the fact that, either directly or indirectly, they were to have a transformative, game-changing influence on the way later artists:

  • Painted reflected light.
  • Approached the depiction of illusory pictorial space.
  • Explored whole-field colour relations.
  • Ramped up the colourfulness of their paintings.

Too often in the past the focus has been on Pointillism as a method, treating it as a fascinating, but not so very important phase in art history. In contrast, in my book, I show that the ideas behind Seurat’s innovations, as developed and transformed by his successors, were to open up possibilities of permanent value for anyone who makes paintings of virtually any kind. With hindsight we can see that Seurat’s ideas:

  • Furnished one of the two pillars that underpin the transformative use of colour found in the work of numbers of progressive artists, including Gauguin and Bonnard. As we shall see in later chapters, when we come to the subject of whole-field colour relations, the artist primarily responsible for the other pillar was Cézanne. It was these two sets of ideas that were to be synthesised in the dogmas of Marian Bohusz-Szyszko.
  • Opened the way to scientific experiments that supplied coherent insights into the working principles of the eye/brain systems that enable the perception of surface-solidity, surface-form, in front/behind relations and the qualities of light (reflected light and ambient illumination). Since it is the operation of these that make possible the only way  that artists can use colour/lightness relationships to deceive viewers into interpreting the content of paintings as existing in illusory pictorial space, it is hard to exaggerate the practical value for painters wishing to represent any of the above mentioned qualities in their work.

To prepare for grappling with all this, it is helpful to be clear about the role that the light reflected from surfaces has in creating our sense of their solidity and our perception of both their form and their interconnectedness.




Three images by artists whose work and ideas contributed to the synthesis of Professor Bohusz-Szyszko

The two practical dogmas taught by the Professor are:

  • No repeated colour.
  • All colour must be mixtures containing a proportion, however small,  of complementaries.


reflected light
Seurat : La Grand Jatte (detail) in which the artists demonstrated his idea for “painting with light” by making sure that all colours are optical mixtures containing complementaries.


reflected light
Cézanne “Old woman”, in which no colour is repeated and, probably, all colours are mixtures containing some proportion of complementaries.


reflected light
Bonnard: “Interior with Marthe”: No colour is repeated and all colours are mixtures containing some proportion of complementaries.




Posts relating to other chapters from “Painting with Light and Colour”:

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Questioning the ideas

Introducing Chapter 2

Chapter 1 of my book “Painting with Light and Colour” told of the dogmas of Professor Bohusz-Szyszko and his claim that they were “all you need to know about painting”. It also praised their value as a practical guide.

Chapter 2 is about doubts that arose concerning their theoretical basis. It was the experience of living with these that prepared me for a critical moment in my life. This came several years later while I was reading an article in the Scientific American that had been brought to my attention by one of my colleagues in the Psychology Department at the University of Stirling. The purpose of the article was to present what the author, Edwin Land, fervently believed to be a mould-breaking understanding of the neural computations used by the eye/brain to produce the phenomenon of “colour constancy”. Actually Gaspard Monge, a French mathematician, had beaten him to the post by nearly two hundred years. But this did not stop the contents of Land’s article from being the catalyst to the evaporation of my worries. More importantly, my efforts to better understand the significance of Land’s ideas were eventually to open the way for cooperations with colleagues in the The University of Stirling Vision Group (see link below*). Without their help, few of the new insights relating to the use of colour in paintings that can be found in my book would have materialised.

But this is jumping the gun. First click on the link below to access the chapter on the doubts that had haunted me and on the process of questioning they set in motion. Its function is to explain why there is a need for the new ways of thinking and doing that play such an important part in the chapters that follow.




The multicoloured display used for the cover of the “Scientific American”, in which can be found Edwin Land’s  definitive demonstrations of the phenomenon colour constancy.


* Above and in many places in my books, I acknowledge the importance of the role of colleagues in the development of the new science-based ideas put forward in them. As well as acknowledging the help of various individual scientists at the University of Stirling,  I call attention to the role played by the University of Stirling Vision Group. For more on this please click here to access the Post I have written on its personnel and its activities.


Posts relating to other chapters from “Painting with Light and Colour”:

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Traditional ideas on trial

Introduction to Chapter 4

It is well known that the Impressionists and their immediate successors (often referred to in my books as the Early Modernists) reacted strongly against what they saw as the straitjacket of the traditional ideas taught in the academies. The purpose of this Post is to publish Chapter 4 of “Painting with Light and Colour”, which provides a short introduction to what these actually were, with comments on the pros and cons of following them uncritically. Normally, I have been writing a separate introduction for my Posts but on this occasion I have used the Introductory from the chapter itself. Accordingly, when you open the link to the chapter below, you may want avoid reading the same thing twice.

Traditional ideas and their limitations

This chapter has four main purposes. These are to:

  • Introduce some traditional ideas about the depiction of space and light.
  • Discuss their limitations.
  • Suggest that these are more comprehensive and satisfactory alternatives.
  • Prepare the way for a better understanding of the significance of Seurat’s science and his colour based innovations.

The first of objectives is met by elaborating on three aspects of painting which, after being explored in some depth by the Renaissance artists, became embedded in the academic tradition. Although satisfactorily serving their purpose for the artists who followed them, it was these that were found wanting by the Impressionists. More importantly in the present context, it was also these that were given a new dimension by Seurat and those who built upon his ideas. The three aspects were detailed in the last chapter:

Significantly, as we shall see, it is only with respect to the first item on the list (atmosphere) that colour of any sort was seen as having a role to play. Even then only blue was required.

In contrast, the academic rules guiding the depiction of the quality of light and shading provided no function to colour. The practice of the Renaissance artists and the teaching of the Academies placed the emphasis exclusively on variations in “lightness” (what the English call “tone” and the Americans term “value”).




3 images illustrating traditional ideas of aerial perspective

tradtional ideas
Leonardo da Vinci – Mona Lisa.


traditional ideas
Claude of Lorraine – Seaport at sunset.


traditional ideas
Turner – Rain, steam and speed.


Posts relating to other chapters from “Painting with Light and Colour”:

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New science for Modernist artists


The science referred to in the title of this post had a lot to do with the revolution in the understanding that gave birth to what we now know as the science of “visual perception“. The first intimations that an important change was afoot came in the later part of the seventeenth century with Isaac Newton’s work on the composition of light. However, the paradigm shift came in the late eighteenth century when the work of Gaspard Monge and others made it clear that colour is not a property of surfaces but is made in the head. This completely new understanding of the nature of visual perception was to be fleshed out in the next century by a flood of confirmatory studies. A milestone was the publication by Herman van Helmholtz of a three-volume review of the new domain of study. It was a magisterial achievement that showed why, despite his considerable debt to others, he has been described as the “Father of the Psychology of Perception“. The third and last of these volumes was published in 1867, just in time to have a profound influence, first on the young Impressionists and, then, in the remainder of the nineteenth and in the early twentieth centuries, on many of their Modernist Painter successors.

The new science misrepresented

One of the purposes of “Painting with Light and Colour”, my book on the theory and practice painting, is to provide a better account of the hugely important role of the new sciences of vision and visual perception in the history of painting. In this post I am publishing Chapter 5, which continues the process of setting the scene started in the Introduction to the science at the beginning of the book. It does so by revisiting and shedding new light on important aspects of colour theory. It has four objectives:

  • To question the widespread dissemination of half-truths and falsehoods in how-to-do-it books and articles on painting.
  • To sort out misconceptions about colour theory that I have found to be common amongst my students.
  • To show how well-known concepts are given new significance when considered in the context of the realisation that colour is not a property of surfaces but is made in the head.
  • To introduce other more recent ideas that will play a key role in the chapters that follow. These are likely to be unfamiliar to most people, as they are the fruit of little known, late twentieth century experimental clarifications, which enable sense to be made of formerly unsolved mysteries.



new science
Forêt de Chateau Noir, by Cézanne, a reader of articles by Helmholtz


Posts relating to other chapters from “Painting with Light and Colour”:

Other Posts on light and colour in painting:

List of all Posts so far 

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