Adventures in the way we see

Marina Warner applauds an illuminating and subtle study of the meaning of colour.

Visitors struggling with midwinter gales past Eduardo Paolozzi's sculpture of Sir Isaac Newton in the forecourt of the British Library will understand the work differently after reading John Gage's second volume on the history and meaning of colour. The sculpture adapts William Blake's famous watercolour (itself a variation on a Michelangelo ancestor of Christ) which shows the great scientist of optics bent over with a pair of dividers unweaving the rainbow as he demonstrates that white light is produced by a bundle of colours: the sum of the spectrum. In a tour de force of interpretation, Gage relates this image to Blake's symbolism of the rainbow, which the poet saw not as the liberating promise of divine forgiveness and hope, but of the watery abyss in which God wished to keep humanity captive: "The divided light of the rainbow was (for Blake) a perfect image of the divided and fallen material world; and in portraying Newton in the act of creating this division ... Blake invented one of the richest images of materialism in art." This is a subtle, difficult reading of two symbols - the man of science, the rainbow - most commonly perceived as enlightening, and it is absolutely characteristic of the energy of Gage's mind.

"Colour must redirect the history of art towards the assessment of the visible," Gage writes, "and this alone should put it high on any future art-historical agenda." It is his achievement that his studies not only make the case for his chosen topic, but succeed in changing the nature of the visible itself for his readers. Colour has a history that can be illuminated by art criticism and theory, philosophy and physics; but too often the terminology and concepts with which it has been surrounded (like "pure" or "natural", "primary" and "secondary") have been taken for granted and thus "exempted from historical analysis".

Yet what a treacherous wild moraine this history proves to be, where naming gives no dependable guide: the medieval word bloi , which gives us English blue, meant yellow as well in France, and xanthos , Greek for blonde, as in Aphrodite's hair, was translated as viridis or indicus - surely greeny-blue? - in Latin by Guido Antonio Scarmiglioni, a pioneer in optical science in 16th-century Prague. Language merely stumbles after the nuances of perception: the eye sees colours for which there are no words, and painters create hues for which there is no logic (Wittgenstein's "reddish-green").

Some of the central conceptual puzzles remain: the number and even the sequence of colours in the rainbow, despite children's mnemonics, are still undecided - indeed, perhaps undecidable. Newton opted for seven colours, but only because, in a spirit of Neoplatonist idealism, he wanted to harmonise them with the musical scale. The identity of the primaries was a matter of continual dispute. Around l715, the German artist J. C. Le Blon pointed out that "all visible Objects" can be painted with "three Colours, Yellow, Red and Blue", which mix to black together, but Goethe opted for two, yellow (light) and blue (darkness), which combined to make purpur (red), and so he too opposed Newton, arguing that colour also inheres in darkness. Many colour charts and colour wheels attempted to settle the question of complementary colours, but this task is fraught with even more complexities. Winifred Nicholson in England and Frantisek Kupka in Czechoslovakia are among several painters who created their own tables and rules, making different arrangements that vary in practicability.

After Colour and Culture (l994), it did not seem that Gage had left many lacunae, so magisterial was that historical survey of "Practice and Meaning from Antiquity to Abstraction". But Colour and Meaning whirls off in an exhilarating wind-rose of new directions, extending Gage's fundamental arguments into fresh zones of often recondite learning: pre-Columbian jadeite and turquoise masks and figured and chequered textiles; the "laws of simultaneous and successive contrasts" drawn up in l828 by the chemist Michel-Eugene Chevreul for tapestry weavers at the Gobelins factory; the excitement that arose in Symbolist circles over the question of " audition colorée " (coloured hearing), otherwise known as synaesthesia; the attempt to develop a metaphysical and affective vocabulary of colour in theosophical thought, and its influence on its adherents among artists, such as Mondrian and Kandinsky; the uses of chromotherapy for diagnosis of personality, as theorised in the 1940s by Max Lüscher.

The accent here falls on the 17th century onwards, though the author's knowledge of classical and medieval sources furnishes insights throughout. In some cases, Gage revisits themes and artists in the earlier work, but he takes the explorations further; his scrutiny of pointillism versus "flat tints" (Seurat and Signac versus Cézanne) has the effect of opening one's eyes to the techniques of painting and to the material polymorphousness of painted hues, so that one truly feels one has never seen before these artists' heroic struggles to represent the visible. Qualities of tone, texture, lustre, saturation, filminess, materiality are all given acute attention here: the wonder of the world's colours and of art's grows page by page. Reproduction of course has posed a problem, even more acute in the rather brief, recent era of colour printing - Edgar Wind being of the opinion that black and white, showing tonality in painting, often surpasses colour printing. As such things go, the plates in this book are of sumptuous quality; nevertheless, it would be a worthwhile endeavour to put a book such as this online, for the range of tints available digitally far exceeds the four-colour minglings of print production.

The book's central argument confutes all notions of innate or inherent colour, as value and even as perception. "One of the greatest achievements of Newton," writes Gage, [IS] to have shown that all colour is intrinsically subjective." It cannot be parted from its theoretical, practical and social contexts to communicate in and of itself alone. The same colour in a painting conveys a gamut of meanings, from marking its likeness (the colour of the object in space) to its freight of symbolism. It is perhaps easier to accept that scarlet might signify differently for a Coldstream guard, a cardinal, a master of hounds, a demon in hell or a Chinese bride, than to relinquish the notion that colours are imbued with intrinsic properties, that red communicates warmth, for example, or blue cold. Yet gas burns blue, and the fiery ether was depicted in indigo-grey whorls of cloud up to the 17th century. Looking at the psychological associations, especially in the theories of Franz Marc and of his friend and colleague Wassily Kandinsky in his crucial essay of l912, "On the spiritual in art", Gage muses on the shifts in gendered hues even among such close associates.For Marc, blue expressed the male principle in action ("The Blue Rider" was the name he adopted for his school of painting) while for Kandinsky, following the ideas of Madame Blavatsky and Charles Leadbeater, blue and violet stood at the cool, moist, female pole, as it did for the Romantic Novalis, questing for the enigmatic "Blue Flower".

Gage's is a partisan enterprise: artists are often shown worrying away with more subtlety and assiduousness than scientists at a problem, with important repercussions for theories of perception and cognition. Around 1820, for example, the English portrait painter James Northcote was visited by a fellow artist, James Ward, who found him holding up a painting to "the fading twilight", watching with some irritation as his paints changed colour, the reds turning dark, "indeed almost black, and the light blues turn white, or nearly so". This trick of the light, at the time T. S. Eliot aptly called "the violet hour", was scientifically recorded and named "the Purkinje effect" after the research of the Czech scientist Jan Evangelista Purkinje about five years later. It is likely, however, that painters - and countrymen and women - had noticed this instability of colour at dusk long before. In the case of Georges Seurat, the artist undertook his theoretical struggles "in silence", proceeding practically as he applied his grasp of complementaries to make the canvas so vibrate with coloured dots that the gaps between the dots started to shimmer and materialise the ghosts of hues that materially were not there.

Henri Matisse emerges as a wide-ranging, scientifically curious reader, who was communicating his excitement at Raymond Poincare's theory of matter and movement to Andre Derain in l916: "Movement exists only by means of the destruction and reconstruction of matter," he quotes, with evident resonance for his own radical attenuation and reduction of kinetic forms. His bold use of blocks of blacks at the beginning of the century may convey his quick grasp of the significance of X-rays. Theories of "black light", developed by Hippolyte Baraduc, a doctor who made images, in the dark, of the vibrations of his patients' souls, and by the scientist Gustave Le Bon, pre-date Matisse's experimental paintings, such as Portrait of Mlle Yvonne Landsberg of l914, showing curving bands of force springing from her head and body against a black background.

Today, supermarket shelves, man-made fibres, film and video, glossy mags and travel ads, mail-order catalogues and posters on the tube have saturated the environment with unprecedented colourfulness. But Gage questions whether this can be seen as simply "the emancipation of colour in the modern world". His work suggests that the heyday of chromatic adventurousness took place between Goethe's ground-breaking study of l810 and the painterly innovators at the beginning of this century; it does not appear that anything comparably exciting is happening now in the practice of physics and art. But perhaps this will change.

Colour and Meaning includes a superb, far-ranging bibliographical essay, which will remain an indispensable guide for any student of the subject; the notes include forays into scholarship in a score of disciplines and as many languages (the author confesses to having had Polish material read for him), and give references to unpublished PhD theses, exhibitions and scientific articles. This study leaves its subject fabulously enriched and adorned, yet still miraculously unexhausted; Gage is an art historian who challenges all laziness of perception, again and again ventilating the stale rooms of received ideas, and he has shown great generosity here, flinging open doors of perception through which many more historians, scientists, artists can pass, towards further experiments and adventures with the ways we see.

Marina Warner recently gave the Tanner lectures at Yale University on "Spirit Visions". No Go the Bogeyman will appear in paperback next month.