I think jet black hair usually looks lovely on *just about* anyone from a woman with deep ebony skin, to an Asian person with 'light-yellow' skin, to a naturally blond white woman like Niki Hilton. I think the only people it sometimes looks harsh on are those with extremely pale skin.
Beyonce has a lovely bronzed look to her skin and I think jet black hair would look very beautiful and natural on someone with her coloring.
My coloring is similar to Faith Evans/Jasmine Guy and I used a jet black Bigen color once several years ago and thought it looked very nice. I received lots of compliments on it. It came out very shiny, too, and that was important to me. I know I wouldn't have liked it if the color had been flat and had not reflected light well.
I will admit that the first time I saw a photo of myself with the color I was a little taken aback because it was quite dramatic. But it was nice. I never used a black color again, though, but maybe I will someday.