> I find it quite telling that you are surprised Greeks might be considered anything but white, while not showing any surprise about Turks. I don't think there's any difference in skin color, so that confirms my suspicion that "whiteness" isn't just about looks.

There are many more people of Greek descent than of Turkish descent in the USA. It's very possible that the person you replied to is simply not familiar enough with people of Turkish descent to express surprise at your claim.