Ancient Egypt = Africans. Moses passed for Egyptian. Jesus is a descendant...
(A lot of times people tell me that Egypt wasn't black because northern Africans weren't as dark as Sub Saharan. Norwegians are lighter than Greeks but I do believe they all are considered "white". If a northern African from thousands of years ago found himself in America in 2014 he would be considered black. So yeah.)
Archaeological and Historical evidence points to the Exodus never having happened. Looking at things from a scientific background ethnically the Jewish population which Jesus descended from is from the Levant and would likely look very similar to modern middle eastern Jews and other ethnic groups from the Levant region. Basically he would almost certainly be of middle eastern appearance, certainly not white, but not black either, simply a typical middle eastern man.
`Israeli archaeologist Ze'ev Herzog provides the current consensus view on the historicity of the Exodus: “The Israelites never were in Egypt. They never came from abroad. This whole chain is broken. It is not a historical one. It is a later legendary reconstruction—made in the seventh century [BCE]—of a history that never happened.” `
`Finkelstein and Silberman argue that instead of the Israelites conquering Canaan after the Exodus (as suggested by the book of Joshua), most of them had in fact always been there; the Israelites were simply Canaanites who developed into a distinct culture. Recent surveys of long-term settlement patterns in the Israelite heartlands show no sign of violent invasion or even peaceful infiltration, but rather a sudden demographic transformation about 1200 BCE in which villages appear in the previously unpopulated highlands; these settlements have a similar appearance to modern Bedouin camps, suggesting that the inhabitants were once pastoral nomads, driven to take up farming by the Late Bronze Age collapse of the Canaanite city-culture.`
If we're going by scientific evidence then there's no proof Yeshua ben Yosef (what Jesus would have actually been called) existed at all and we are doing something along the lines of debating Black Adam's ethnicity.
Eh, that is debatable. If we assume that he was completely a fictional character, we would still find it most reasonable to assume that he was of the same ethnicity of most people of the region he inhabited given that the bible makes no particular effort to give an exact description of the physical appearance of Jesus and makes no assertions of him being of a different ethnicity than those around him. We know for certain that the bible states him to be of the Jewish people, and knowing the ethnic background of the Jewish people, it follows then that he would be of a middle eastern complexion as are the inhabitants of the Levant