Greeks will not like this thread.
I think they were even darker than modern Greeks. Paintings and physical descriptions by themselfes indicate it.
Xenophon describes the Ethiopians as black, and the Persian troops as white compared to the sun-tanned skin of Greek troops. Herodotus similarly used Melanchroes "dark-skinned" for the Egyptians and he compared them to the Aithiopsi "burned-faced" for the Ethiopians.
Polemon of Laodicea in Physiognomica notice differences between Greeks and Populations of the North. He came to conclusion that Greek superiority stems "from their medium skin tone". He thinks light hairs and pale skin are sign of barbarism, blue eyes indicate poor eyesight according to him.
Every Greek depiction got black hair at least if not brown skin too. Only Gods associated with sun and brightness(holiness) or mythological heroes are sometimes described as blonde (aphrodite).