Changing Usergroup colors with skin?

[mme42]

Is there a way to have different usergroup colors for each skin/theme? Here is the problem. We have quite a few different groups and to make sure that all the groups are distinguishable from each other, we've ended up using black for a usergroup. Our themes have light backgrounds, so everything works fine at the moment. But, I'd like to make a new theme with a dark/black background, and that would make the black colored usergroup unable to be seen.

So, I thought that if I could make it so the black usergroup switches to white or light gray when the dark theme is used, it would make things a lot easier. I guess I could also make sure there is a colored background everywhere that usernames display so that there is enough contrast between text and backgrouind. Or I could go back to the drawing board and try to find new colors for all groups so that nobody is using white or black. I'm just looking for other options.

Is there a way to do this? If not, how do you deal with usergroup colors when using light vs. dark themes at the same time? I'm new to making themes, so I'm sure I'm missing something.

Thanks