Most of the “Black” leaders in America are actually mulatto.
The original Spanish/Portuguese word is derived from the word for "mule" because the mule is a cross between a horse and a donkey. So the term could be considered disrespectful, but I don't know if anyone is offended by it. Although in America, it is a safe bet that every possible word is going to offend some group or another.
Most blacks in America are actually mulatto. The gene mixing started even before the African slaves got off the ships, and continued for over a hundred years, afterwards.