The Zuni tribe in the USA speak ancient Japanese.
This is true, I heard about this some time ago.
As for blue eyes, some Ainu had/have brown eyes, green eyes, and blue eyes. Although my father's side looked very much Ainu, his eyes were brown. As for every blue-eyed person having one common ancestor, I don't know about that. It's like the assumption of many scientists that everyone descended from a single female ancestor, "Lucy", in Africa. It sounds sketchy to me. Life, and mutations, likely occurred in many different places, at least IMO.
Jim