I have been re-texturing some characters and I really want to make my elites shiny and with small lights on their armor. The multipurpose bitmaps help the game to identify those lights in the bitmap and give them this extra shiny and bright color? Anyways, how do I make a multipurpose bitmap? You need a special tool or you can do it with a regular image editor?

Wow, thanks for the super quick responses guys! Those tutorials look great! Thanks a lot!