In a group of three people (A, B and C), everyone has a different hair color (blond, black or brown, not necessarily in this order) and everyone may be either a knight (always telling the truth) or a knave (always lying). This is what they say.
- Blond-haired person: "C has brown hair".
- Black-haired person: "C is a knave".
- Brown-haired person: "A and B are knights".
Determine the hair color of C.