Is it wrong to make jokes about minorities?
It depends on what the purpose of the joke is. If it’s stam leitzanus then, of course, you can’t. But if it’s leitzanus of avodah zarah, then yes. Leitzanus of idolatry – of false religions, of false beliefs – yes. But you have to know how to make leitzanus. Not just to be a leitz. You can make leitzanus – but you can’t be a leitz.
Like the Navi says about the idol. It was an idol with a big belly and the Navi said that this idol apparently has constipation. He’s trying his best to relieve himself but nothing helps. That was said by the Navi in order to impress on people how empty is the worship of idols.
But leitzanus itself is absolutely wrong. And to make leitzanus of people because they’re black or brown doesn’t make sense at all. Being black or brown is no sin. You can’t make leitzanus about that.
Now, leitzanus of leitzim, maybe. But the Gemara says “kol leitzanusa asira, bar me’leitzanusa d’avoda zara.” That leitzanus is mutar because that leitzanus is da’as. It’s a clarity of mind. There is nothing more important than da’as Hashem – than thinking along with Hashem. In order to make clear to ourselves – and to others – how wrong and foolish their beliefs are, it’s worth it to make leitzanus of them, and to thereby show how silly their beliefs are.