by John Gage
Thames and Hudson pounds 32
We are halted at the traffic lights by the colour of fire and blood, and ordered to drive on by the colour of growth and new life. Red strikes us as warm, and green or blue as cool, though the sober scientific truth is that red comes at the long-wave, low frequency end of the spectrum, with the least capacity to heat. But how do we define "red", "green" and "blue" in the first place? The human brain, according to John Gage's fascinating, dauntingly erudite study of colour, can discriminate literally millions of colour sensations, of which we give names to only a tiny fraction. Compared to our perceptions, our language of colour is drastically impoverished - around a dozen basic terms in most languages. With typical good husbandry, Nature has been loath to provide us with a special kind of receptor for each shade of colour, perhaps because the permanent hallucination which might result would mean a short life but a happy one. The English painter John Constable, who was famed for his sharpness of vision, seems to have patriotically detected only red, white and blue in the rainbow, as opposed to the six or seven tints portrayed in it today.
The hunt for "basic" colours, in a forlorn attempt to stabilise these varying shades, is as old as the hunt for the Holy Grail. It is probably just as futile: the idea of basic colours, for example, seems largely absent from Latin American cultures. In antiquity and the Middle Ages, various so-called "basic" colour-sets have almost nothing in common with each other. In medieval times, as well as in some non-Western languages today, the same word could be used to cover both blue and yellow, while in Old French a single term could do service for both red and green. The same word in Irish, "glas", can mean green, blue or the colour of gin, and Irish males have been shown to have problems in discriminating between them, not only because of the influence of the latter. For Isaac Newton, gold was a lot closer to red than it was to yellow. Not all human cultures see white as positive and black as negative; for an important strain of Christian mysticism, God is a deep and dazzling darkness. The development of oil painting, which allowed artists to produce different colours by mixing a basic set of them together, buttressed the belief in certain "primary" tints; but Gage shows how deeply this was shaped by symbolic considerations, such as seeing the colour spectrum as a kind of musical harmony.
There is a two-word phrase in one of the Inca languages which means "parading about the town dressed in red". With other peoples, however, a disdain for colour has been a mark of distinction and refinement, which is one reason why Renaissance noblemen and modern bridegrooms can be found wearing black. Though whether black is a colour is another bone of contention. The painter Henri Matisse paradoxically saw black as light rather than dark, which some critics associate with the prosaic fact that he had moved from a well-lit studio to a dark one. But he may also have been influenced by the discovery of X-rays, which since they acted like light but remained invisible, struck some observers as a kind of black light.
Colour-defective vision is nearly a hundred times more common among white males than white females, and age can make a difference too. The strident red of some of Monet's later work may well be an effect of cataracts. Even so, there may be a sense in which all our perception of colour is defective. Brown, for example, seems not to have emerged until fairly late in the history of painting. Until the 17th century, colours were generally thought to be as objective as earwigs or earthquakes; it was only with the optics of Isaac Newton that the notion that they might be all in the mind began to surface. If we moderns classify colours primarily by their hue, the Middle Ages saw them as different degrees of brightness. What defined a pigment for them was where it came between light and dark. Since they were not looking at exactly what we are looking at, the same word for them could cover hues as varied as fiery red, ice-blue, and a sandy yellow with an olive cast. And if some cultures have no word for particular colours, the Chinese use a phrase meaning "red-red-green-green" to mean colourful.
For the painter Turner, colour and light were actual substances; for the ancient Greeks, colour was more a matter of surface than substance, giving no clue to the real nature of things. The idea has survived into our own time: "colourful" suggests vivid but flashy, as in the phrase "a colourful character", and can have mildly negative overtones. Deeper issues like truth and falsehood are colourless, even if we allow for a grey area of uncertainty between black and white. Colour for us tends to be strictly skin-deep, whereas depths are murky. This is a curious belief, since the depths closest to us - our entrails and viscera - are pink and purplish; but we continue to think of them as dark, no doubt meaning that they are invisible.
How we define the word dark, however, is another fraught question. For the early Middle Ages, blue (the favourite colour, incidentally, of modem Europeans) was akin to darkness; it was later shifted up the colour-scale towards light, perhaps under the influence of stained glass. Its symbolic value seems to have shifted along with it. Purple had enormous prestige in ancient times, as the most heavenly of all tints; but though blue inherited this august status in the Middle Ages, it could also represent the dark angel of evil. However, the blue pigment made out of lapis lazuli, known in Europe as "ultramarine", was reserved for such precious bits of a painting as the Virgin Mary's mantle because it was both costly and durable.
In fact the only sure thing about colour symbolism seems to be its utter arbitrariness. By the age of Romanticism, blue was a mysterious colour which stood for spirituality, though later on it was also seen as calming, depressing, peaceful, nostalgic, melancholy and dreamy. For some colour theorists, blue was at the cool, feminine end of the spectrum, in contrast with the warm yellow-orange of the male. For others, colour itself was feminine, as opposed to the masculinity of drawing. One 19th-century German painter identified brown hair with naivety and roguish innocence, and blond hair with modesty, solitariness and good-heartedness. Black hair, he thought, expressed either a cool, proud personality or a cheerful, happy one, thus covering his rear as cannily as any fortune-teller. Kandinsky saw green as a boring, inert, complacent colour, and thus an apt symbol of the bovine bourgeoisie.
If shades are hard to define, so are the sounds which colours make. The early 20th century witnessed a growing interest in synaesthesia, or the blending of different senses, a faculty which is apparently much more common in women than in men. An English questionnaire on the subject in 1992 elicited 210 responses from women but only two from men. Synaesthesia is obviously a cissy affair for males, though it yields some surprisingly impressive findings. A recent study of nine female students found a high degree of consistency in the way they attributed white to O, white or pale grey to I, and yellow or light brown to U. Another study found that Czech, German, Serbian and Russian speakers tend to see E as yellow or bright green.
If these experiments reveal a remarkable degree of consensus about colour, not much else in human history does. A work by a 19th-century art teacher expressed the hope that a scientific colour-system might replace such impressionistic terms as "dove-grey", "dead leaves", "thigh-of-excited- nymph-pink" and "Dauphin's poo". Some American clothing catalogues today boast equally fanciful colours: "burnt toast", "mint julep green", "roasted aubergine". But for all scholarly energy lavished on this question through the ages, we seem to be stuck in the end with Dauphin's poo. It is an irony of this magnificent study that it wheels in the heavy guns of optics, politics, economics, art history, psychology and theology only to teach us how chancy a thing colour is.