>>27258We have detailed historical accounts and/or DNA evidence for the races of the three examples I gave (Egyptians, Romans and Native Americans). I didn't mention Greeks or Turks, but I am sure that plenty of historical evidence exists which describes their hair color, migration/conquest history, and racial history.
As for Sumeria, yes, I admit that it's speculation, but I'm not making a very extraordinary claim. All I'm saying is that it seems within the realm of possibility. All the people who live in that region of the world are some variety of Caucasoid. Caucasoid people are capable of having blond hair and fair skin, and it's also very easy for them to lose these phenotypes with enough intermarriage with swarthy Caucasoid people, possibly invaders, as happened in Egypt and Italy.