As a black person, I never viewed Piccolo as "black" in anyway way, even when I was watching the dub.
I've said before that I don't look to Dragon Ball for deep, complex storytelling. It's the same thing when it comes to representation. It's not something I particularly look for in Dragon Ball. This is a simple martial arts story written by a Japanese guy in the 80s who initially made his name writing low-brow humor for kids. Representation is not something I expect to be on the mind of someone like that.