Some have gone out of their way to post instructions, and ColorWare will even do it for you. Is this movement a worthy successor to the Japanese cult of the PowerBook 2400? Also, because I couldn't find any way to fit them in with the rest of the post, here's an oldish story about someone who built a case out of Legos for his PowerBook 5300, and here's someone else who painted his Wallstreet PowerBook G3 a nice cherry red.
iBooks in many colors. The tronBook may be old news, but it has helped to set off a wave of iBook modifications, all very pleasing to the eye.