I think you read the same info I did..From IMDB:
Vin Diesel was born Mark Sinclair in Alameda County, California, along with his fraternal twin brother, Paul Vincent. He was raised by his astrologer/psychologist mother, Delora Sherleen (Sinclair), and adoptive father, Irving H. Vincent, an acting instructor and theatre manager, in an artists' housing project in New York City's Greenwich Village. He never knew his biological father. His mother is white (with English, German, Scottish, and Irish ancestry), and his adoptive father is African-American; referring to his biological father's background, Diesel has said that he himself is "definitely a person of colour".