A friend of mine had a black eye bruise that was truly black. He got punched by a guy who was much bigger than him right in the eye and it was black and swollen for well over a week. For the first two days he could barely see out of it.
Honestly, though, it serves him right. He was being a huge jerk that night and if I was the other guy I would have punched my friend too. A buddy is a buddy but everyone can cross the line.