What kind of paint does light go through?

Acrylics and oil paints are out of the question. Heat from the bulb could melt, set fire to, and/or vaporize the paint. There are some paint pigments that are downright toxic and you don't want to be inhaling their vapors.

Here's another (remote) possibility, paint could trap the heat and the bulb might explode.

I'm guessing paint safe for decorating glass would not work with the heat from the bulb.

You still have two options.

1. Call up the bulb manufacturer and see if they have a "paint" that you can use on your bulb.

2. Contact a store specializing in lamps and lighting. See what they would recommend.

Artist and Designer, U.S.

glass colors used for glass paintings. that will be the best as it looks almost like glass once it's dried.

try it. :)