AITA for rapping as a white person?

AITA for rapping while white?

I mentioned I rap for fun and produce beats to a few coworkers, I am white and that’s important to this story. An Asian coworker at work called me racist for stealing black culture and I should stick to producing. I’ve never heard anyone say that before and I was a little taken aback by that accusation. Is rapping as a white person racist? Is my non black coworker allowed to get offended even though the culture I was enjoying wasn’t his either? I’m genuinely curious is that racist and AITAH?