A QUESTION OF COLOUR

When you're choosing colours to distinguish three teams or three players you will automatically go for three primaries - red, yellow,blue. They are the most easily distinguished. But suppose you're designing for four teams - what's your fourth colour? Green, of course.

But why? Green is only one of three available secondaries. Why not orange, why not violet? But we all feel that green is the most distinctive. Orange might be a sort of weak red. Violet might be a kind of cool red. But green is no sort of yellow.

Why does green have this dominance over the other secondaries? Is it a matter of optics, something to do with how our eyes work? Or how our brains distinguish the messages that the retina sends? Is it a matter of familiarity - green being the most common colour to appear to us in large areas?

Or is it just tradition? Are children brought up to regard these as the inevitable four colours? Are school house sports teams distinguished by coloured motifs any more? I doubt if any infant minds are now greatly impressed by long winter evenings playing halma - if, indeed, they ever were.

Odd, this business of coloured playing pieces. Chess has only two uniforms, Black and White. Even if the exquisitely turned oriental pieces on the board are dyed crimson, officially they are Black. Strangely for a mathematician, Dodgson got it wrong. His Red Queen is the Black Queen of chess notation. But I suppose he wrote from the child's point of view, where the pieces are described as they appear on the board. Tenniel's illustration, being monochrome, would serve for either.

And while we're thinking about colour - what is happening to traffic lights? Clever lads were always keen to point out to their grandparents that the green lights were in fact blue-green to compensate for the yellowing effect of the foggy English climate. But now they seem to have gone turquoise. Are the authorities aware of some impending change in the colour of the atmosphere?

I have my doubts.