Black'd Up is a form of Ethnic Mutation. This happens when a white guy is subjected to rap music and cadillacs. This usually happens in america as when a "Black'd up" person is seen, he/she/it is hired by the local white people to work in the cotton fields and sell drugs to other white people. you can usually tell if someone is "Black'd up" if they have curry coming out of their pockets and chicken wings under their $2 loin cloth.
"Yo that motha fucka is Black'd up"
"Wot u on about you Black'd up motha fucka"