It’s doubly cheating: there’s no intelligent choice in the colours, and the shapes (and ground) are being filled by a PostScript fill call rather than with a painting algorithm. This is all temporary. In particular, working out why some random colour schemes are better than others will help to decide how to choose colours more intelligently.
rob-art: Colour For Cheats
I’ve had a busy evening. Some of the better results from purely random colour choosing: