Hair color of the Proto-Slavs (revisited)

In Hair color of the Proto-Slavs, I presented a few pieces of evidence about the hair pigmentation of the most ancient Slavs. The existence of Baltic admixture in some Slavic groups may indicate the element responsible for the depigmentation of these groups; indeed, the Baltic area is the "nexus" of depigmentation among Caucasoids. Recently, I have also discovered an additional source providing additional evidence for this hypothesis:

Следует отметить, что на северо-западе Восточной Европы славяне, в отличие от балтов и финно-угров, обладали более темным цветом волос и радужной оболочкой глаз. Не случайно во времени Киевской Руси они называли балтов и финно-угров "чудью белоглазой"

It should be noted that on the northwest of East Europe the Slavs, in contrast to the Balts and Finno-Ugrians, possessed a darker color of the hair and iris. It is not by chance, that in the time of Kiev Russia they called the Balts and Finno-Ugrians "white-eyed Chudes" (?)