Quoting: Proud2bNaija
The neutral Polish term for a black person is Murzyn (plural: Murzyni). The term czarnuch (pl. czarnuchy, from czarny = "black") is considered offensive.
And you are right. "Czarnuch" basically is a derogatory name for a black man. However I've noticed that young gangsta rap fans sometimes address themselves that way, just like black gangsta rappers address themselves with the N word. At the beginning it probable was more of tongue in cheek while with time it became norm, so now in some contexts.
It also can be considered neutral, I think.