Vin Diesel was born Mark Sinclair Vincent in New York City, the son of Delora, a psychiatrist and astrologer. Diesel has Italian and African American ancestry. He has described himself as "definitely a person of color" and stated that he is "of ambiguous ethnicity - Italian and a lot of other stuff". Diesel has never met his biological father, and was raised by his African-American stepfather, Irving, an acting instructor and theatre manager.http://en.wikipedia.org/wiki/Vin_Diesel
If he is of African-American ancestry, then he's a 'person of colour' but that doesn't mean he's black; it is quite possible he has black genetic history. There are recorded instance of mixed-race people being born and looking completely 'white'-- not 'albino' white, but 'white' in the Aryan (meaning originally from the Himalayas, not Nazi) sense. (Remember, Europeans-- 'white people'-- are descendent from the 'Aryan' tribe which has its roots in India. It is entirely possible for two brown-skinned persons to create a 'white' looking child; the reverse is not true.)
So, while he is not black, he is certainly a person of colour. The two terms are not necessarily interchangeable.