I use colored compact fluorescent bulbs on yard stakes for some of my lighting. I use clear jugs or 2 liter bottles with the top cut off as covers and poke a few holes in them above the bulb around the sides, but not on top with a soldering iron to let excess heat out. Mine ae hidden behind objects so the jug is not visible, just the light. Position the jugs carefully so the bulbs don't touch or get too close to the sides. Standard bulbs, or black light bulbs will be too hot to safely do this with.