Buy the Paint
Carefully wipe the surface with a 50:50 mixture of rubbing alcohol and distilled water. As it dries, visit a light fixture store to get an idea of the current trends in light fixture finishes. Keep in mind the style of your home. If your house is decorated like a Spanish hacienda, then a black matte finish would be a match. A contemporary or modern home might benefit from a painted chrome finish. Buy spray cans of Rustoleum paint for metal or another spray product designed for use on your light fixture's material.