https://www.newscientist.com/article/2467926-most-europeans-...
https://www.biorxiv.org/content/10.1101/2025.01.29.635495v2....
"The peoples of Europe are fair-skinned and reddish, because they live in a cold climate and are not scorched by the sun."
Source: Hippocrates, On Airs, Waters, and Places, 5th century BC.
"The physical characteristics of the Germans are consistent: blue eyes, reddish hair, and large bodies."
(Tacitus, Germania, chapter 4)
Egyptian tomb paintings from the New Kingdom (c. 1550–1070 BC) visually represent foreign peoples with distinct skin tones - "Europeans", in the form of Sea Peoples or early Aegean peoples (e.g., Minoans or Mycenaeans), were sometimes shown with light red or pale skin tones.
I am open to this hypothesis (conjecture?), it just lacks supportive evidence. On the other hand, we have ample evidence that agricultural revolution did not "turn people white" in the other regions.
From a cursory study of Wikipedia my rough summary would be: Europe used to be roughly divided in the "Western Hunter Gatherers" (WHG) and "Eastern Hunter Gatherers" (EHG). The WHG typically had dark skin, dark hair and blue eyes, the EHG were typically light skinned with brown eyes. Blond hair may have originated from EHGs in North Eurasia and spread from there. Around 6000 BC farmers from Anatolia (~modern Turkey) started moving into Europe, the EEF (Early European Farmers). Those were typically smaller than European hunter-gatherers, light skinned and dark haired. They migrated North, partially replacing the EHG and WHG, partially mixing with them, and in some places the EHG and WHG simply took up farming. But Easter Europe is less amenable to farming, meaning the dark-skinned WHG diminished the most while the light-skinned EHG and EEF became the dominant groups in Europe's genetic diversity
1: https://en.wikipedia.org/wiki/Early_European_Farmers#/media/...