See balls, Quidditch.
See black beetle.
See Black family.
Rubeus Hagrid's eyes are black (PS8)
Harry Potter's hair is black (PS1), as was that of James Potter (OP28)
school robes are black (PS5)
Snape's eyes and hair are black (PS8)
Albus Dumbledore's eyes are blue (PS1)
Ron Weasley's eyes are blue (TLC)
Harry turned his teacher's wig blue (PS6)
Hermione Granger's hair is brown (PS6)
Ginny Weasley's eyes are brown (CS3)