I was looking into this as well, dung beetle rainbow black or metallic pearl green would be nice.
http://forum.ppcgeeks.com/showthread...=black+housing
I am guessing you could use acrylic paint on a regular housing for different colors. Perhaps air brush the housing.. Don't know if you would have to prepare the surface or prime it to hold, as most of those cheapy covers found at the mall kiosk tend to chip and flake.. Atleast you could attempt to paint the unit without taking it apart, just cover up the parts you don't want painted really well.
Would be nice if there was a way to rubberize color coat the housings
Humm Home Depot sells that rubber handle stuff for tools... humm..
-CC