Colour Theory in Fine Art Painting
COLOURS IN FINE
For the definition and meaning of
In this article we examine a few of the basic colour concepts underlying the theory and practice of colour in fine art painting. Before we start, however, please note that most colour theory is still in its infancy. The science of colour-optics remains somewhat confused, while colour-psychology is still highly underdeveloped. To illustrate how far we have to go to properly understand colour, and its effects on the human eye, consider this: computers are capable of identifying up to 16 million colours, while humans can detect up to 10 million: yet there are only 11 basic colour terms in the English language - black, white, red, orange, yellow, green, blue, purple, pink, brown and grey. Indeed, 11 is the maximum number of basic colour terms to be found in any of the 98 languages studied by anthropologists Berlin and Kay during the 1960s. Until we find a way of familiarizing ourselves with a greater number of identifiable tonal variations, our knowledge of colour theory and its underlying concepts is bound to be seriously incomplete.
HISTORY OF COLOUR
The word "colour" describes the appearance of pigmentation of objects, resulting from the light they reflect. A synonym for colour is "hue". Paint colours may be made lighter or darker by adding white or black respectively. A lighter version (eg. pink) of a particular colour (red) is called a "tint"; a darker version (eg. magenta) is called a "shade". So far so good. Now comes a trickier word - "tone". It's tricky because it is sometimes used to describe both tints and shades. Technically however, it describes the relative dull or bright variants of a colour that are obtained by adding grey (that is a mixture of white and black).
Several terms are employed to describe the relationships between different hues. "Primary colours" refers to those colours from which all other colours derive. There are three primary colour models: Red, Green, Blue (RGB); Red, Yellow, Blue (RYB); Cyan, Magenta, Yellow (CMY), depending on the context. "Secondary colours" means those colours produced by mixing primary colours - eg. on the CMY scale: cyan + yellow = green; yellow + magenta = red; magenta + cyan = purple. "Tertiary colours" refers to colours created by mixing a primary and a secondary colour, or two secondary colours.
The Colour wheel, of which there are several versions, is a circular diagram which displays a number of colours arranged roughly in order of their appearance in the spectrum. Most colour wheels include three primary colours, three secondary colours, and six tertiary colors - a total of 12 main segments; some colour wheels feature more intermediates, adding up to 24 segments. The colour wheel is the main diagramatic model for explaining relationships between colours, although it is of limited practical value because, in reality, colours tend to behave and react with each other in less exact ways.
These are the hues which sit directly opposite each other in the colour wheel: for example: Purple and Yellow, Red and Green. Colour Complements are colour opposites and contrast each other in the most extreme way.
The first theories about colour were propounded by the Greek philosopher Aristotle, who maintained (in De colouribus) that the two principal "colours" were white and black - light and its absence - and that all colours derived from one of the four elements: air, water, earth and fire. He also maintained that the true primary colours after white and black are yellow and blue: since we "see" the sun's pure white light as yellow, and the blackness of space as blue sky. As you can see, Aristotle's theory of colours took a philosophical rather than a scientific approach.
Leon Battista Alberti
Next came the colour ideas of the major theorist of Italian Renaissance art, Leon Battista Alberti (1404-72), expounded in 1435 in his inspirational handbook Della Pittura (On Painting). In Della Pittura, which became one of the major sources for later treatises on fine art painting, Alberti states: "Through the mixing of colours infinite other hues are born, but there are only four true colours from which more and more other kinds of colours may be thus created. Red is the colour of fire, blue of the air, green of the water, and grey of the earth... white and black are not true colours but are alterations of other colours." Without going into detail, Alberti maintains and extends the general Aristotlean approach, minus black and white which are demoted to non-colours. Although his theoretical contribution to colour science was thin, Alberti did have quite a lot of advice for painters about the use of colour, like which pigments and which tints and shades were appropriate.
Sir Isaac Newton: The Colour Spectrum
The next major person to address the fundamental concepts of colour was the scientist Sir Isaac Newton, whose discovery of the colour spectrum together with his theory of colour (outlined in his later treatise Opticks, 1704) - continues to shape the debate. It was Newton's prism experiments in 1666 that furnished the scientic basis for the understanding of colour. In these, Newton proved that a prism separated white light into a range of colours (which he called a "spectrum"), and also that the recombination of these spectral hues re-created the original white light. Although the spectrum was continuous, Newton identified 7 different colour-segments (by analogy with the 7 notes of the music scale) which he named red, orange, yellow, green, blue, indigo and violet. All other colours in the spectrum were created, he hypothesized, from these 7.
Goethe, Chevreul & Others
Subsequent scientific and optical investigations, as outlined in such works as Johann Wolfgang von Goethe's Theory of Colours (1810) and Michel Eugène Chevreul's Law of Simultaneous Colour Contrast (1839), concluded (1) that the three primary colours were red, yellow, and blue (RYB); and that all other colours could be created through various combinations or mixtures of these primary colours, or their children; (2) that this theory of colour-mixing applied equally to the behaviour of light colours (beams of light) added together (additive mixing), and coloured pigments added together (subtractive mixing).
While the first conclusion was mostly true, the second was false. This was because the absorption of light by material substances (like pigments/dyes) follows different rules from the perception of light by the eye.
Towards the end of the 19th century, scientists in Britain and Germany found that the perception of colour is best understood in terms of a different set of primary colours - red, green and blue/violet (RGB) - using a light-based model. Later study by experts in trichromacy revealed that these colours are perceived in special ways by three types of colour receptors or cones in the retina.
Finally, 20th century industrial chemists studying the mixing of pigments and dyes discovered that the behaviour of these materials is best described and regulated by using a third colour-model based on the primary colours cyan (a blue), magenta (a red), and yellow (CMY). In the printing industry, because these pure pigments are expensive, the colour Black (K), is substituted for equal parts of CMY to lower ink costs, thus producing a fourth colour-model, the CMYK system. These important scientific advances were somewhat muddied by a range of populist books such as Modern Chromatics (1879) by the US physicist Ogden Rood, and colour atlases produced by Albert Munsell (Munsell Book of Colour, 1915) and Wilhelm Ostwald (Colour Atlas, 1919).
Primary Colour Theory: Summary
If the above history sounds rather convoluted, here in simple terms are the basic principles of colour mixing theory, as follows:
1. In the mixing of paint-pigments and other dyestuffs (called "substractive" because it involves the absorption or selective transmission of light), the primary colours are cyan, magenta, yellow - the CMY system.
2. In the mixing of beams of light (called "additive" because it involves the addition of spectral components), the primary colours are red, green, blue - the RGB system; or red, yellow, blue - the RYB system.
3. In general, painters typically use red, yellow, and blue primary hues; while psychologists, colorimetrists and other colour scientists use red, green and blue; and industrial chemists involved with dyes or paint pigments use cyan, magenta, yellow primaries.
According to the principles of colour theory, the effect of painted colours on the viewer will vary considerably depending on the combination of hues present, their luminosity and the purity of their colour. To understand this, imagine you are looking at a painting of a typical red British post-box.
Colour psychology works like this: as light strikes the eye, each wavelength does so slightly differently. Red, the longest wavelength needs the most adjustment to look at it, while green requires no adjustment whatever and is the most restful hue. In the eye's retina, these vibrations of light are converted into electrical impulses which travel to the brain - ending up in the hypothalamus, which controls the endocrine glands, which in turn regulates our hormones. Put simply, each colour (wavelength) focuses on a particular part of the body, stimulating a specific physiological response, which in turn evokes a psychological reaction.
It is also conceivable, though not yet scientifically proven, that colour/light enters our bodies through our skin. Considerable anecdotal evidence indicates that some individuals can differentiate colours with their eyes shut, and certain blind individuals remain susceptible to colour psychology.
There are four psychological primary colours - red, green, blue and yellow.
Importance of Tones in Colour Psychology
Even though the above four colours may have particular attributes, it does not follow that (say) all yellows or all reds have a similar effect. As in fine art painting, tonal variations can have a significant influence on the psychological impact of the colour. A light-red neck-tie or scarf, for instance, may have a completely different effect to that achieved by a normal-strength red. A warm daffodil-yellow is likely to be perceived quite differently from a cold lemon-yellow.
Role of Colour in Public Places
A useful indicator of the effects of pigments on the human brain and/or emotions is the role that different colours play in point-of-sale graphics and posters. What colour is a can of Coca Cola, for instance? Also, consider what colours are used in major institutions, such as hospitals (light blues/greens - never reds or yellows!), banks (neutral hues) and so on. By comparison, shops, art galleries, and schools often use bolder colours like yellows combined with reds and blues.
For information about oils, see:
Oil Painting: History, Painters.