Just a suggestion, Maybe give players a set of effects for powers along with the custom colors?
Like energy attacks, say give a set of effects to choose from, like beams, blasts, obs or whatever. But giving a choice for effects would be a great tool for getting a specific theme or look your trying to build.
Blade weapons, why no energy blades? We all want laser swords and blades, why not have a option? Bow weapons with energy strings or arrow effects would be a nice thing too.
Master Minds, I would suggest a group of looks for the minions chosen. Or even just the colors of their gear, so they actually match yours.
Just a few ideas, we need more options and i hope more ideas if you have any.