Yes, but when the ancient Greek describe "blonde" they aren't referring to the same colors we associate blonde with. Alexander the Great's hair was said to be xanthos.... Contemporary depictions of him are with light brown or chestnut colored hair.
The greeks of today aren't necessarily representative of what the greeks back then looked like.
Yes, because a lot of Greek people have some Slavic lineage in their family history and are lighter skinned than ancient Greek would have been.