Not so. Says Hodgkin: "I'm not a colourist - although, of course, all artists are colourists in a sense. You have to think in terms of hues. Look at a Vermeer. Just take one tiny section from any of his paintings and look at the colours. He's a colourist. And look at the 'greyness' of Corot. Now there's a great colourist. Colour is in all painting - even in the greys and browns of classical Cubism." Hodgkin abhors the sort of thinking that eventually brought Josef Albers to the conclusion that all mixed colours were somehow impure, corrupted. This, after all, was nothing more than an updating of the medieval painter's dictum which stated that the more brilliant and primary a colour, the more divine it was.
As Hodgkin says, today pure, bold, primary colour is often perceived of implying innovation. Since the Impressionists, the Modernist ethic has held that art should progress by way of increasingly unnatural colours. "If it's bright it must be modern. But think of Titian. Too often bright colour is just a disguise for bad painting. Think of the Scottish colourists. Mostly they were dreadful."
For Hodgkin, colour is only a tool, like form and facture, just one part of the vocabulary of his painting. "Colour for me is always functional," he says. Hodgkin's worries about the unwonted pre-eminence of colour do not appear to be shared by other artists of his generation whose work similarly engages the viewer through pure chromatic brilliance.
John Hoyland paints dramatic, acrylic abstracts with an immediately recognisable morphological signature, seeking, through their spontaneous pyrotechnics, to convey to the viewer something of his own inner visions.
"I've always had a desire for colour," Hoyland says. "An English Romantic obsession with the South. Colour is desire made concrete. Matisse spoke of colour's power to heal. He said that colour mustn't just clothe form, it must constitute it. Colour cannot be separated from form." And in all his paintings it is the colour that creates the form. But can colour in itself be enough?
For 40 years, Patrick Heron has been using pure colour. He is synonymous with his large, resonant canvases - what he calls "wobbly hard-edged paintings": dazzling juxtapositions of violet and orange, green and scarlet. Heron admits to the presence of forms in his paintings. Perhaps since, for him, under the guiding influence of his two great mentors, Matisse and Bonnard, colour is not so much a means of conveying emotion but of realising space. He also attests to the power of pure colour to create a heightening of the senses - a natural high. Colour can be hallucinogenic; "The finished painting," he has said, "should end in pure sensation of colour." As early as 1962 Heron declared: "Colour is both the subject and the means; the form and the content; the image and the meaning in my painting." This he has subsequently simplified to "colour is paint".
Another of Heron's contemporaries, Gillian Ayres, seems to see colour in a similar way: "At the end of the day," she says, "colour, quite simply, is light. You can't have non colour in a painting. Even a dirty smudge, or what is apparently black or white, resonates with colour. I don't think in terms of tone, I think of hue. That's all that is important. Colour is a bloody moody thing."
She's right, of course, and here is the heart of the problem with colourism. Colour is essentially unclassifiable. In the past, artists and theorists have tried (see palette, below). Goethe, believing he could chart the effect of colour on the mind, declared in 1810 that certain colours were positive and others negative, some hot, others cold. He was followed in 1839 by Michel Chevreul and subsequently by Kandinsky, Albers and scores of others. But the effect of colour, although pigments might be subject to the laws of physics, defies definition by rule. It is subjective, emotional, personal. Colour is essentially ambiguous. Red might well imply danger, but it can just as well mean passion or the promise of the seductive, sexual warmth of Matisse's Red Studio. Likewise, do we, in 1995, still universally associate blue with the Virgin's robe? Surely blue can now stand equally for cold or for the hot blue flame of a gas burner; for the emptiness of Klein's void or for the solace of a calming spirituality.
As Hodgkin would have it, though, colour is neither consolatory nor soothing, merely functional. This again seems surprising for an artist whose paintings of Venetian evenings or Indian sunsets seem fixed in the sublime melancholy of the Northern Romantic tradition, and whose colours seem to operate with Proustian directness in attempting to recapture an elusive memory. But he is adamant. "Colour," Hodgkin says, "is just what's going on in the painting."
So what conclusions are the inheritors of the tarnished lamp of colourism - including such wunderkinder as Fiona Rae, Callum Innes and Gary Hume - to draw from the experience of their elders?
The revealed truth about colour is this: that, however hard we try, whether we use it to convey specific space or emotion, or simply lose ourselves in its ambient depths, colour cannot exist independently. It is always destined to be imprisoned in both form and rhetoric. Similarly, colour and meaning - symbolic, emotional, metaphysical and spatial are irrevocably inseparable. If this begins to sound familiar, don't be surprised. Hodgkin has, in effect, manoeuvred himself out of one tradition and into another. In 1843, when asked to explain the meaning of his painting The Morning after the Deluge, Turner replied simply: "Red, blue and yellow."
n Howard Hodgkin's 'Venetian Views' is at the Alan Cristea Gallery, 34 Cork Street, London W1 (0171-439 1866) to 22 Dec
n Patrick Heron's work is included in the third Annual Display, Tate Gallery, St Ives (01736 796226). The exhibition has just opened and will run for a year