I have posted on the existence of blonde hair amongst some Melanesians before. There are natural chemical treatments as well as extreme malnutrition which can result in blonde hair in dark skinned people. The latter seems unlikely from the photos I’ve seen (the lightening of hair due to lack of food has been reported in African refugee camps). In regards to the former I’m confused as to why chemical treatments would be common among Oceanian people as disparate as Solomon Islanders and central desert Australian Aborigines, and yet not among many other east Eurasian populations.

In any case, in response to this comment below on Negrito appearance, I started using google images, and I stumbled upon something strange. In my Malaysian Negrito sample there’s a division between two ethnic groups, Kensiu and Jehai. The Kensiu have hardly any Austro-Asiatic or Austronesian admixture compared to the Jehai. When I looked for images of the Kensiu I came upon on this page, which seems to relate an experience of an aid worker in an isolated Malaysian village. The inhabitants were ethnically diverse, some Malays, but indigenous Negritos a well. Well, it turns out that some of ...