It’s not likely that they are descended from a pre-IndoEuropean coat of paint as it were.
https://freerepublic.com/focus/chat/3997572/posts?page=83#83
https://pubmed.ncbi.nlm.nih.gov/19862808/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6244411/
https://www.quora.com/Is-Rh-negative-more-common-in-Indian-tribes