@thack45,
Why does it sound racist?
To be honest, I know the story of Santa and Zwarte Piet, since my father grew up in Holland, and I have never associated Zwarte Piet with an African.
But that might be due to some other conditioning. In Norway we have the expression "svarte per", which also translates to "black pete". It means a person who conducts shady activities, or who has trouble keeping on the right side of the law. It has no relation to black human beings, but rather to the idea that people who do illegal or dishonest things don't want light shed on it, hence "black".
It's not racist. But if some black human being came and accused me of being racist on the background of the expression "svarte per", I would even go so far as saying that he is being racist, assuming that I am such a degenerate human being that I use the word "black" to make a negative association to black people.