Racism is power+privilege..something people of color in today’s society do not have.
People of color can be prejudiced of course. For instance if I said “all white people are horrible” or “all Asians should die” then I would be a terrible prejudiced person. But I would not be technically racist because I still have no power over other races the way white people do.
The reason it is racist for white people to appropriate other cultures is because years ago white colonizers came and completely fucked up those cultures. They want to keep their cultures to themselves, and that is completely alright given their history.
Not to mention they have special significance that is destroyed when people don’t know the meaning. Dreads are sacred to African culture. Bindis are sacred to Hindu culture.
It’s really not that hard to just not steal from other cultures.