New categories

@ndonald2 Yeah, this is intended to merge.
I think every project ends up redefining these, and @mgorbach had asked if they were in RZUtils. I'd say that if the only reason not to have them is that they are merely syntactic sugar, then the same logic could be applied to the `rz_colorFrom8BitRed` type methods as well. On the other hand, people won't have to rewrite them each time.