Yeah, I've thought about doing a thick CP in colored plexi (like blue or red), and then lighting it from behind, but the bottom would be nasty with the wires and control stick bases...it might be difficult to pull off.
Here is what I've thought about though...perhaps I shouldn't say anything, but I guess I'd be over it if one of you guys did this and posted the pictures.
Do the CP in thick colored plexi. Mask off a design on the back and paint the rest black. Then light it up from behind.
This way, you just see a lit up colored design in the CP, and not the whole underside. You can cover up the button/stick bases and route the wires away from the design. It would look pretty pimp IMO.