png transparency

I really need the help of the theming community on this one. It has to do with the way color.module fundamentally works and how it works with themes.

The comment here linked me to an implementation of a color-changing theme for joomla. It uses alpha-transparent PNG images and pure CSS to deliver theme changes on the fly. From the looks of it (I do not have an account there yet, but I'll buy one), essentially the layout is comprised solely of CSS and colorless transparent images.