Adam made the 1st sin. The other tribes, peoples & nations had not sinned.
Most "white" people are descendants of Adam and have sin printed in their Adamic genetic code. It is quite likely that the other peoples on Earth learned about it from Cain, and subsequent sons of Adam & Cain.
When Christ spoke about overcomers in Revelation, He was talking about people who overcome their inherited genetic urge to put their desires first and ahead of the Creator's Perfect Word, Logic & Intent. Even Christ, the Messiah had to overcome that genetic heritage during that 40 days fast he took in the wilderness.... perhaps the wilderness of self.