Kennewick Man died in Washington State, 9,300 years ago. He was Ainu of which there are still 10-50K still living in Japan. They have many Caucasian features. You may find this link interesting.
Also, there are many Chinese poems lamenting the green eyes of the Han Emperors. And...their 'magic-men' were noted for having red hair.
I just read your kindly offered article of The Samurai and the Ainu. At the bottom of the article it say:
Comment. Fringe anthropology notes many "white" races in strange places; viz., the white Indians of Panama and the Mandans of the American West.
I live in Panama and there are NO white Indians here. The author is confused with the Kuna Yala Indians who live in the San Blas Islands (Atlantic coast). They have a high rate of albinos due to their closed society (interbreeding) and not due to being some kind of white race.
Again
there are no white Indians in Panama.