The Benjaminites were one of the twelve tribes of Israel, being the descendants of Benjamin, the youngest of Jacob's 12 sons. So they were Hebrew, or Jewish or Israelite, depending on the time in history. At a larger level, they, like the other Jewish tribes, were Semites, and spoke Hebrew, a Semetic language.

So the answer would be olive to a dark tone, right?

Benjamites are a tribe of Israel. Overall, Israel was a very diverse people. Abraham was from Ur of the Chaldees "beyond the [Euphrates] River" (Joshua 24:3), which excludes Ur of southern Mesopotamia since it was on the west side of the River. The northern Ur was not far east of Haran in northern Mesopotamia, and its inhabitants were fair-skinned. Rebekah was also from there, as were Leah and Rachel and their handmaids. Their father's name Laban means "white." Overall, ancient Israel was fair-skinned, but intermarriage with the Canaanite population caused a darker diversity among the tribes. In Egypt, Israelite slaves were depicted as blond, red, brown, and black hair; brown eyes and blue eyes. Israel was diverse. King David had red hair and blue or green eyes (ruddy = admoni in Hebrew = redhead or even blond) (I Samuel 16:12). Solomon had black hair and blue eyes (Song of Songs 5:11-12). Judah typically was darker than the other tribes, as Perez and Zerah were sons of Tamar a Canaanitess (Genesis 38). Over time, Israel in exile has moved around quite a bit, being in hot climates and cold ones. So their skin is lighter in the cold ones and relatively tan in the hot ones. In Jesus' time, Israel seems to have been a rather warm climate, so you could expect the Benjamites who settled north of Jerusalem (some argue they were the Galileans) to have been tan but still ruddy. In more ancient times (pre-exile), the climate was much more temperate and green, so their skin would be fairer. All throughout, though, their hair was usually light-colored, as were their eyes. I hope that helps.