Having "colors" would just confuse people on who is a "higher paid member", a "middle paid member", and a "non-paid member".

I like it how it is - because as long as anyone knows much about chess - it is easy to tell how is the "bigger" people around here - not that the "bigger" people are better then others - just they have paid and have more games and options.

For example it is easy to know not to invite a pawn to my fellowship.