As basic rules of a language must be practiced continually, and therefore are never fixed, so exercises toward distinct color effects never are done or over. New and different cases will be discovered time and again.
I have times when I doubt what I'm doing. When those moments hit, I think about how grateful I am to be able to do what I do every day. It was harder when I started because I didn't see the response, but now I'm out there playing for people and seeing them happy, which makes it all worthwhile.