Actually, this is a very popular theory concerning Christ. Unless Mary and Joseph were from European ancestors, the likelihood of Christ being white is very low.
As a student of history, I don’t know that Christ’s race was ever brought up in the Bible or elsewhere. I welcome any data to the contrary.
I believe, just from reading of the history of the Jews, especially from the time right before Christ, that he possibly was very dark skinned. During the revolt of the Maccabees, many Jewish families moved to from Ethiopia (they had established a second temple there). The possibility intermarriage between the Ethiopians, of whom the Jewish people were always close, and Jesus’ ancestors doesn’t seem a far fetch. The Bible just gives part of the lineage, but doesn’t say who the wives of many of the ancestors were.