"Ancient Babylonia" is a few thousand years, normally divided into much smaller periods, repleat with invasions, wars, uprisings, and other changes of rulership.

For all that, we can assume that the average inhabitant is a farmer speaking a Semitic language - that is, one related to Arabic or Hebrew or Coptic. That translates in appearance to a hard brown tan and black hair. Someone who spent more time indoors, like ladies or priests, would have lighter skin, often rendered in Egyptian art as pale dull yellow.

I must be getting old. When I studied this, no one would have thought of suggesting they were blond, even the Kassite dynasty with their Indo-European names. Seriously, what source claimed they looked Aryan? Has anyone noticed that even Scandinavians are brown-skinned when they are tanned?