I wouldn't shop for a car this old (well some people think Y2k cars are 'dead' old) on basis of colour, you'd be hard pressed to find a specific model in excellent nick in any colour.
I would really like a punto in that really dark graphite grey though.
Although GT;s and sportings look good in broom yellow, dark graphite grey, light grey and I have seen two prestine black sportings knocking about. Both subtly modified (very subtle alloys, lowered a bit, supersprint exhausts the pair of them and very subtle sideskirts and front air dam etc, very subtle and prob my fav mk1 punto (s)