Since the crania from afanasievo cluster with lower volga and since the cultural equipment of Afanasievo is very similar to the Repin culture and Afanasievo started around 3500BC it will be a good indication if proto-indo-europeans had blond hair if we can show that afanasievo people had blond hair or the early inhabitants of the tarim basin that were R1a before the R1b people showed up. The "beauty of Loulan" seems to have had dark hair. Also there is no evidence of farming in the steppes at that time so it doesnt make sense that steppe people would have depigmented due to lack of vitamin D. Did blondism come from cucuteni-tripolye or bug-dniester or later from boat axe people near estonia/lithuania?