During the code sprint at DrupalCon Boston I started an implementation of a color picker for Fivestar. So far we plan to make 6 colors available to certain sets of stars. The stars should be able to support 3 different types of color: solid, linear gradient (top to bottom) and radial gradient. Each state (on, off, hover) gets two of the colors.
This feature should significantly reduce the number of implementations of Fivestar that need to have a special site-specific implementation of a color. Because these new "color enabled" sets of stars will likely replace existing sets of stars, I'll be reducing the number of stars that are accepted for inclusion with Fivestar if they are not color enabled. We should have an example of how to make a set of color enabled stars after the feature is completed.