The idea that eugenics aims at creating tall blonde blue-eyes is obvious enough.
Not in the Space Seed episode. Scotty says they are a mix of people.
MARLA: From the northern India area, I'd guess. Probably a Sikh. They were the most fantastic warriors.
MCCOY: Heart beat now fifty two and increasing.
KIRK: The others?
SCOTT: There's no change, and they're mixed types. Western, mid-European, Latin, Oriental.
Exactly. "Space Seed" makes of point of stressing that Khan's crew is multiethnic. ("Ling! Macpherson!") which is why it's odd that WOK turned them all into Aryan types.