Board Thread:Naruto Discussions/@comment-945885-20140709082448/@comment-24519434-20140718061002

Tunade is technicaly a senju her grand mother was the only one in her family who was Uzumaki, redhair is a recessive trait so minato's blonde hair showed up in naruto. The other Uzumaki are all born from two people in the Uzumaki clan, thats how they got red hair.