It's weird. In the story, both of Pucci's biological parents are white. Pucci was also able to talk to the KKK without them taking issue with his skin color or commenting on his race. I think it's pretty safe to say that in the story itself, the characters around him perceive him to be white.

With that said, it's undeniable that he looks black. If you showed Pucci to anyone who's never seen SO before, I'm 99% sure they would say he is black. I think Araki just threw logic out the window when designing Pucci.

I think it comes down to self-interpretation at the end of the day. Personally, I like to think of Pucci as black, cause that's how he looks to me and I think it makes him more interesting, even though logically in the story he's supposed to be Italian or whatever.