The Indians said they were red-haired.
"The Paiutes and the long-legged redheads did not get along well. The Indians accused the Si-Te-Cah of being cannibals, and waged war against them. The Si-Te-Cah fought back. After a long struggle, a coalition of tribes trapped the remaining Si-Te-Cah in what is now called Lovelock Cave. When they refused to come out, the Indians piled brush before the cave mouth and set it aflame. The Si-Te-Cah were annihilated."
Well, I have a hard time relying on legends from 15,000 years ago, especially since the people telling the legend weren't even here 15,000 years ago.
As for accusing each other of being cannibals, in fact Native Americans did practice cannibalism of their enemies for ritual purposes, hearts and livers mostly.
As I understand it, there was no cannibalism between tribes that were in the same linguistic group, it was done against people in another linguistic group, Algonquin against Iroquoian against Siouxian, but I am not certain of that.