Powerful pigments: An exhibition dedicated to colour

What does colour mean to you? "Little boxes all the same/ There's a green one and a pink one/ And a blue one and a yellow one/ And they're all made out of ticky-tacky/ And they all look just the same."

From Malvina Reynolds' 1962 hit, "Little Boxes". It was a proto-hippie song, which mocked conformity among West Coast professionals, all living in their identical houses. True, the little boxes had different colours. But that only made them more repetitive. Colour, the song implied, is an empty difference. A sequence of pure colours is pure meaninglessness.

A few years later, the German painter Gerhard Richter was on to pure colours too. He began to do paintings that consisted solely of coloured oblongs laid out in a grid: a pink one, a blue one, a yellow one, etc. They were randomly chosen and randomly distributed, and their grids spread bigger. In 1974 he made one called 256 Colours, then another called 4096 Colours.

It was impossible to see these canvases as patterns or abstracts. What they resembled, obviously, were paint-shop colour charts. Like "Little Boxes", Richter presented a sequence of pure colours as something meaningless. But he took a very different attitude to this, a much more positive one. He wanted, he said, "a beautiful meaninglessness". And he wasn't alone.

Have a look at the new show at Tate Liverpool, Colour Chart: Re-inventing Colour, 1950 to Today. There's pure colour in checkerboards, in strips, in blocks, in bands and spots – and 40 artists, from Andy Warhol and Sol LeWitt to Damien Hirst and Jim Lambie. It's everywhere. It's the triumph of Elmer the elephant. What's going on?

From time to time art goes through big changes in its whole sensibility. Once upon a time it was good to be poetic and expressive. Lately, it's been good to be cool and impersonal. Once our idea of colour in art was Van Gogh summoning up his emotional forces or Matisse arranging his choirs into harmony. Lately, it's been Richter's grids, Judd's units, Buren's stripes, Flavin's tubes, Hirst's dots. We avoid at all costs anything that looks too subtle, too sensitive, too spiritual. Blank is beautiful.

Paint here goes down plain, unblended, uniform, the product itself. It follows the words of another artist here, Frank Stella: "straight out of the can, it can't get better than that." And the paint being used, often enough, is not the infinitely responsive medium of oils. It's something inflexible and unmixable like gloss or enamel, with their hard dead shiny surfaces.

Artists take their lead from the industrial and commercial world. After all, be realistic, most of the man-made colours we see aren't brushed on to a canvas. They're on metal or plastic or vinyl, in neon and fluorescent, in car paint, house paint and photographic inks. And they generally aren't composed into complex "relationships". The artists in Colour Chart reject orchestration, in favour of juxtaposition. They like that unfeeling feeling.

And it can be a powerful feeling. Richter was right. There is such a thing as beautiful meaninglessness. A dense field of randomised colour-elements provides a total sensation. Nothing is missing. By comparison, every other painting seems partial: it does it one way, and not another way. The colour chart painting does it no way, and every way. It delivers the sense of completeness that other art can only dream of.

There are other feelings here too. There's dry wit, as in Bruce Nauman's Sunproof Drawing, not a drawing but an early photocopy of an actual colour-chart, advertising a brand of paint called "Sun Proof". Made in 1961, it was naturally a black-and-white photocopy. Sun proof it wasn't. Over the years its greys have all turned to shades of brown – a bit more colourful, then.

There's elation too. Some of these pictures are in fact good old uplifting abstracts, however much they try to keep a pokerface. Ellsworth Kelly's Colors for a Large Wall is a chequerboard whose primary colours are aerated with lots of whites. It makes it a bright and breathing surface. And there's Jim Lambie's ZOBOP!, using his trademark décor, a floor filled with multi-coloured tape-strips in layers that bounce away from the walls in a ripple-resonance effect. It's a pop-culture version of First World War dazzle camouflage.

But a lot of the time you're simply registering a slightly amazing fact. There really are a lot of pictures from the last 50 years that look like colour charts. Jim Dine. Giulio Paolini. Jennifer Bartlett. Richard Serra. Byron Kim. Sherry Levine. David Batchelor. Wow, they've all done them. And then, at a certain point, surprise turns to boredom. Another criss-cross formation of plain colours, and another...

Well, this is an exhibition curated by art historians. They have a point to prove, and they've done their homework, and their evidence certainly mounts up: OK, we surrender, the colour chart has indeed provided a template for a remarkable number of works. But evidence doesn't necessarily make for a lively show.

And if artists, say, or even art critics, had done the curating instead, there might have been a more various agenda. How about including contemporary colourists like Bridget Riley or Howard Hodgkin who resist this historical tendency? Wouldn't they do something interesting to the mixture?

How about old artists like Seurat (dots) or Mondrian (checkers) who seem to anticipate this story? And how about those early Renaissance artists, who used ultramarine blue for the Virgin's cloak – pure colour, "straight out of the can", and used not for its expressiveness but for its expense? Isn't that another anticipation of "colour chart" attitudes?

Pure colour has a wide repertoire. There's the cool, methodical, mechanical sensibility, which this exhibition mainly explores. A few years ago, however, there was a show at the Barbican, with several of the same artists on show, which had an opposite emphasis. Pure colour was a real blast – a ravishing, disorienting, anarchic sensory force, beyond language, beyond reason, mind-blowing and body-shaking. "Located within the realm of desire and provocation, the exhibition seeks to show that where language falters, colour takes over." An exaggeration, sure, but an important counter-view.

And then there's another powerful approach. The colours: they're a gathering of separate identities. See them in a group, one by one, side by side, and you're drawn back to childhood, and the intense relationship you had then to the colours as individuals. You were learning their names, and learning to use colours as names themselves – a way of dividing up the visual world.

Shapes, bricks, tiddlywinks, letters, crayons: there's the green one and the pink one and the blue one and the yellow one. Colours needn't be either blanks or explosions. They're badges. They're characters. And this response can last into adulthood, too. Think of the bundle of hues that mark the London Underground map – or wherever this map-model is imitated. Think of the colours in flags or uniforms. Colours are always on parade.

And though you wouldn't guess it from Colour Chart, even a list of pure colours is capable of the most delicate poetry. Take this short text-piece by Thomas A Clark, made last year. The seven colours of the spectrum are printed in black-on-white - "red orange yellow green blue indigo violet" – except that "orange" is printed in orange, and "violet" in violet. Title: Still Life with Fruit and Flower.

'Colour Chart: Reinventing Colour, 1950 to Today' at the Tate Liverpool; until 13 Sept, closed Mondays; admission £7.80 with concessions