Noah took his sons and their wives with them. Did each husband have multiple wives of different races? The only reason I ask is because it’s confusing that all life was destroyed on earth, leaving Noah and his family to repopulate the earth. Now, if Noah and his sons and their wives were all from the same region, then it seems everyone on earth that resulted from all those years of re-populating would all generally have the same skin color, bone structures, features, etc.
According to 1 Peter 3:20, there were only 8 humans on the Ark. They were Noah, his 3 sons and their four wives. Genesis 10 lists a total of 70 sons and grandsons of the three sons of Noah, and all the people groups of the Earth have descended from these 70. Japeth became the Patriarch of the European and Asian races, Ham was the original ancestor of the African people, and Shem fathered the Jewish and Arabic tribes.
Because God gave each tribe a different language when He dispersed them from Mesopotamia in Genesis 11, they became isolated from one another and very little inter marriage took place. Because of this, the dominant characteristics of each group actually grew to be more pronounced over time. Experts say that within a few generations the major differences in physical appearance were pretty well established.