Okay, it's an old question but we haven't examined it here yet so let's have your thoughts.
Adam was the progenitor of the whole human race, from his genes sprang the negroid, caucasian, mongoloid, indo-european and every other race on the planet.
The Hebrew people were not selected as Jehovah's chosen nation until Abram had found favour with God so presumably all races were equal in His eyes before then.
So then, what basis is there, if any, for deciding what Adam and Eve's skin colour may have been?
Could they not indeed have been black or blonde or Chinese looking?
This is a pointless discussion I grant you. Skin colour doesn't matter. Still, it could prove interesting!
Nic'