Why do these only ever seem to come in black or silver??

http://www.bigappleherp.com/Light-Heat-Reflector-Domes?sc=2&category=22

I need one in WHITE so it will blend into the background of my dining room, and I can't find one! I need it for a mercury vapor lamp so I don't dare get one intended for home use.

Or can you paint those things w/ fireplace paint? It's supposed to be able to withstand high temps.