I wouldn't use just run-of-the-mill hardware store black paint, although it may work. I'd use hobby-grade paint such as "Tamiya Color" for polycarbonate. I've had great success with thier Gun Metal Grey #PS-23 on lenses for other projects as well as RC bodies for nitro cars and trucks. Tamiya makes about a bazillion different colors with varying opaqueness for the hobby market, so almost any local hobby store should stock it. Pick out your color and do a little test work on a piece of glass to get your desired effect. Best of luck and have fun!! Just remember to start out with light coats, until you get the shade you want. The cap color is what you would get with several full wet coats so you can easily adjust your color palette with lighter coats!