"Know what'll go over great? Just being straight up racist. That's always funny, gets the crowd going"
When you have these thoughts, I highly suggest you resist them in the future. It's definitely not gonna down the way you think. You're not 11 anymore, and the uncomfortable chuckles you might get from them are decidedly not actual mirth.
Edit: two reasons it's racist. One, mistaking people of another race for each other. Two, and much more important, it is a misogynoir stereotype that black women look like men. In an age of transvestigative douches harassing people at restrooms, maybe we don't propagate that kind of stuff right now.