Chevreul ‘s work on colour covered many aspects of the subject. To explain relationships between colouırs he designed a 72 part colour wheel, which I’ve attempted to copy in my exercise on complimentary colours. It shows the transition of colours between primaries, and demonstrates how complementary colours are opposites.
His book ‘Chevreul on Colours’, published in 1839, is a practical course of study on colour, with some simple experiments that demonstrate his discoveries, and some strategies that enable artists to clarify, intensify and harmonise their colours.
He starts by explaining that objects don’t possess colour of themselves, but that colour is perceived through light reflected to the viewer’s eye. And that this perception could be altered by the reflection of light from objects nearby. He describes the effects of juxtaposed colours, or contrasts, of which he defined three types; simultaneous, mixed and successive.
C states that where the eye sees two juxtaposed colours, they will appear as different as possible, both in colour intensity and tone, above all on the borders where the colours are juxtaposed.
When observed adjacently, colours (particularly bold colours) and tones influence each other, creating an optical illusion that appears to lighten or darken the hue or tone.
The eye perceives a slight halo of a complementary colour around a coloured object. Eg a red object has a green halo & vs, so if red is actually placed next to its complementary, green, each colour will appear more vivid. But while complementary colours clarify and purify each other, by the same token non-complementary juxtapositions muddy each other. There is similarly a phenomenon of the simultaneous contrasts of tone. A light colour imparts a darkening to a darker neighbour, and itself appears lighter.
The phenomenon of simultaneous contrast only exists where the two colours are of sufficient size. If the areas of juxtaposed colours are small, they tend to fuse, giving an impression of a third colour – C called this a mixture of colours. (Pointillists, impressionists).
This is sometimes called colour fatigue – if we look at any colour long enough it eventually appears duller. But, the initial vibrancy is restored quickly if we just look for a moment at a spot of its complementary colour. Painters, said Chevreul, should rest their eyes periodically so their work doesn’t become drab.
This is analogous to the notion of an afterimage – if we look at a colour for a long time then glance away we see its complement for a moment – in fact we see a flash of colour that corresponds to the whole object.
Chevreul’s influence on artists
Chevreul didn’t actually recommend the painting of simultaneous contrasts of colours, nor did he advocate using dots of colour designed to enhance brightness, but he did discuss the application of his theories to all fields of art and crafts , and so he provoked an interest among artists, many of whom adopted his theories on these subjects into their work.
He had good advice to give to artists on the effects of light on colour; To summarise – Light falls on objects from several sources, all of which alter colour perception (tone and hue) –
- Direct light eg the sun
- Diffuse light eg daylight
- Reflected light
He explained different ways to use colour and tone to harmonise a painting. In a monochrome painting, for instance, tones could be deployed either in a scale of small increments, or in only dark to light contrasting tones. In a coloured painting one could use all bright, high key colours; or all closely grouped, dark colours. Both these would possess harmony of tone. Alternatively a contrast of tone balancing, say, bright colours through darker passages of muted shadows. Another suggestion Chevreul made was that a composition with many disparate colours could be unified by imposing an overall coloured light – this could be achieved by a coloured glaze
As a director of Dyeing and senior chemist at Gobelins, the famous tapestry manufacturer, he was more than anything interested in the influence that two colours placed side by side have on each other, which is the situation painters are constantly confronting.
Many painters at the time were searching for ways to enhance their colours, and popular interpretations of C’s law provided them with a technique – they found a recipe for this in the juxtaposition of complementary colours. Painters were also anxious about colour harmony, and C provided them with rules on this too.
Delacroix was one who was interested in enhancing his colours through juxtaposition of complements – The Crusaders Entry into Constantinople demonstrates Chevreul’s theories – see the juxtaposed red and green flags on the floor – although it’s colours are deteriorated and hard to make out now. He made a mnemonic drawing of the complementary colours which he used for harmonising colours in his painting.
The impressionists adopted the law of simultaneous contrast in their paintings extensively, possibly by natural instinct. Pisarro was the most interested in colour theory. He often used simultaneous contrast by careful selection of the colours of clothes – in the painting below he draws attention to the head of the figure by giving her a red headscarf, the complement of the adjacent green.
I also noticed the optical mixing of colours to produce a third color in this painting – spots of blue and yellow in the foreground mix to give an impression of green; of red and yellow in the middle ground mix to produce an orange hue.
I found many other examples of the harmonic use of complementary colours in the works of Impressionists; a good example is Monet’s Poppies at Argenteuil. At the same time in the U.S., water colourist Winslow Homer carefully studied Chevreul for most of his career. Chevreul’s book was WH’S bible. There is evidence he studied the theories extensively and put them into practise sometimes designing a complete composition with the specific aim of demonstrating one of C’s observations. He exploited the concept of simultaneous contrast in many of his paintings eg the blue and orange in On the Sands
WH also employed the simultaneous contrast of tone, juxtaposing light and dark to successfully give the impression of an ocean swell, for instance, in his watercolour Hound and Hunter – the effect of the alternating light and dark slashes of tone give the effect of three dimensional wavelets supporting the craft on the surface.
Later in the 19th century artists gradually became less interested in reproducing nature exactly and more in organizing pure colour in their work. Seurat and Signac acknowledged C’s influence. Both used small dots of complementary colour to enhance the luminosity of their paintings. For example in a detail from Seurat’s Young Woman Powdering Herself we can see the juxtaposition of small dots of blue and orange to create luminous flesh tones, and the shining tones of the gold bracelet; these are fuse in the eye when seen from a distance and mix optically, producing a third, different colour.
Note – this only works to increase luminosity if the dots are big enough to be perceived at a normal viewing distance; if they are too small, the colours simply mix to produce grey
Van Gogh was very enthusiastic about Chevreul’s theories and systematically used complementary colours in his search for colour harmony and to convey mood, as he explained in several letters to his brother Theo. Here is his painting Bedroom at Arles, and his explanation of the colours he used;
(Van Gogh, Letter to Theo no 554 in The Letters of Vincent Van Gogh, pp 416-418)
The violet of the walls against the yellow of the bed and chair; the red blanket against the green pillows and curtains; and the blue basin against the orange washstand; form simultaneous contrasts of complementary colours.
C’s theories still proved useful to later artists, in helping them organise pure colour on near-abstract canvases . The Fauves moved away from attempting to replicate nature through colour, and started to use colour in an intense way, expressing mood and emotion over representation. Andre Derain’s experiments with colour at Collioure are full of hot contrasts of complementaries
Red and green are juxtaposed by Matusse too, in Odalisque With Grey Culottes.
Later still, abstract artists were able to use C’s law as a sort of a grammar, to help them construct canvases of pure colour relationships Robert Delauney was an enthusiastic disciple, using the contrast of complementary colours as a starting point for his paintings, and focussing on the sensations produced in the viewer’s eye. Nowadays C’s influence is less directly acknowledged, but still the basis of teaching on colour.