Since there has been art, there have been disagreements about colour – what it means, how to use it, whether it is a good or bad thing.
Vasari held that colore was Venetian, while disegno – roughly, drawing – was Florentine and thus (Vasari was from Florence) better. The row rumbled on for 400 years: drawing was rational, clever, Poussin; colour was sensuous, sensual, Rubens. And so things stood until the 20th century, when two changes took place, the subject of a show called Colour Chart at Tate Liverpool.
The first change was that the number and kind of colours available to artists mushroomed with developments in paint-making. This wasn't just about stuff sold in art shops: for the first time, artists took to buying colours from their local B&Q.
An early apostle of household paint was Picasso, who waxed particularly lyrical about a commercial enamel called Ripolin. The first burst of colour on the dowdy palette of Analytic Cubism came courtesy of Ripolin, in Picasso's Violin, Glass, Pipe and Anchor of 1912.
Largely, though, the hues and tints of hardware paints were still used as a means to an end – to convey mood or rhythm, or to reproduce the warmth of sun on brick. It was only after the Second World War that the idea of color gratia coloris – colour for colour's sake – took off, marking a second phase in the 20th century's chromatic revolution.
Various things brought this about. The first was a rebellion against the valuing of skill which had held sway since Phidias. As far back as 1921, Aleksandr Rodchenko's Pure Red Colour, Pure Yellow Colour, Pure Blue Colour, shown at Tate Modern earlier this year, had hinted that the hand no longer counted in painting – that a canvas covered in a single pigment was as valid a work as the Sistine Chapel ceiling. Still, Rodchenko had made his statement in artist's oils. Now, nonart paints – the kind of stuff anyone might buy and use for anything – brought the point home.
Modernity wasn't going to dwell in an ivory tower, or at least in academies and art museums. It was going to be made in ex-light industrial lofts and factories, and its making would be open to anyone with a tin of paint and a roller. (Or, in the case of Dan Flavin and Donald Judd fluorescent tubes and a steel cutter.)
Commercial paints, familiar to anyone who had ever decorated a spare room or sprayed a bent fender, were a visible sign of what Colour Chart's curator, Ann Temkin, calls the "de-skilling" of art. It was all very democratic, although, as often with democracy, not completely so.
Actually, there were three requirements to being a modern artist: a tin of paint, a roller and an idea. Bound up in the dissing of the hand in art was a new fetishising of the mind – a way of working that Sol LeWitt dubbed "conceptual". LeWitt's Wall Drawing #918, a room-sized work, announces its intentions in eye-frying, shop-bought colours, in the fact that it has a number rather than a name – it, too, might have been ordered from a shop – and that it wasn't made by LeWitt but by his assistants.
In the demotic phrase of the builder's yard, Wall Drawing #918was contracted out, and looks it. Changing attitudes towards colour in the 20th century aresummed up by a sequence of three German artists.
In the Bauhaus of the1930s, Josef Albers painted squares of Masonite, the chipboard of its day, insub-squares of overlapping colours. The beauty Albers sought was of systematisation, a literally chromatic scale to match a musical one. Forty years later, Gerhard Richter up-ended Albers' thinking by painting pictures that didn't just look like colour charts but actually were.
Works such as 1025 Colours are precisely what they claim to be: deadpan recreations of Pantone sheets, a self-referring self-advertisement. Twenty years on from Richter, Katharina Fritsch's Eight Paintings in Eight Colours (1991)shows the impossible position Richter had left her in. If you're a chromatic painter, where do you go from 1025Colours?
Fritsch's answer, a snapshot of art in the 1990s, is to turn the question into a game by putting single hues in big, academy frames.
ColourChart is that engaging thing, a show that takes something familiar and, by focussing on it, makes you see it afresh. By all means go. TateLiverpool (0151-702 7400) to 13 Sep