Forget black, drivers can burn green rubber

However hot your hot hatch is, however eye-poppingly fuchsia your chassis, however sparkling your wheel trims and groovy your go-faster stripes, your car's tyres will be black, because black is the colour all car tyres are. But not for much longer. A technological breakthrough by style-conscious French tyre manufacturers has made coloured tyres possible.

Car tyres have been black because the rubber used to make them is treated with carbon black: an extremely dark, fine, sticky powder which makes the rubber tough and resilient, but also stains it. Several manufacturers are working on alternatives, and the Michelin group has come up with a silica-based additive that has similar resistance-enhancing qualities but is a neutral colour that allows colouring agents to be added.

For the initial batch, rather than shocking pink or bright orange, Michelin has chosen green - but not the muddy olive-sludge shade of Wellington boots. "It's a kind of eau-de-Nil, a lightish, grassy green," says the head of PR, Alan Abercrombie.

The tyres were produced in France, and the first experimental run of 400 is being test-driven on the Continent at the moment, no doubt provoking cries of "Ooh la la! Regardez les pneus verts!" wherever they go.

They have been fitted to smallish hatchbacks that would "appeal to the younger person", says Mr Abercrombie. ("Lady drivers" and urban trend- setters are also seen as potential buyers.) The tyres, which "enable technology and fantasy to go hand-in-hand", can potentially be made in all the colours of the rainbow, he says. "When car manufacturers make special editions, we would be able to add colour-coordinated tyres, though commercial marketing is some way in the future."

Michelin is still gauging the reaction of motorists and conducting final tests on the efficiency of the coloured tyres, which have been manufactured to high safety specifications and are brand-named "Tonus".

But, although full-scale production may be some way off, in this field the French are wayahead. British manufacturers have ignored the style potential of acid yellow and sky blue. One reason is the huge investment needed in new, clean equipment to deal with colours. Carbon black is very pervasive, and even a small amount will ruin a delicate shade of eau-de-Nil. (Its sticky qualities were demonstrated last month when a lorry carrying carbon black shed its load over a 20-mile stretch of Gloucestershire, covering homes, gardens, cats, dogs and herds of surprised cows.) So, for the time being, the style-conscious British motorist is still restricted to a few jazzy decals and a nice new set of co-ordinated seat colours.