Been having a look at a few tyres, are coloured ones a no no.
Why the hell not, I think tyres are probably the most boring part of a bike to look at. There are loads and loads of coloured options but make sure the tyre you're looking at is actually any good - what tyres have you been looking at?
Because they're ugly!
The classic tyre/tubular of black tread and natural amber sidewalls is the best looking of all time:
See this tread re the problem of lack of availability of classic looking tyres:
It seems tyres and rims are the parts which are most hard to get right. I've seem so many bikes which are otherwise great looking but have ugly modern rims and tyres (including ugly all black tyres).
The only other colour which is acceptable is the special record attempt type of track tub with a translucent latex tread.