Who was the first black human?

No one knows when any of the races became distinct.

Adam's genetics made EVERY race possible with a wide variety of hair, skin, eye color... (Acts 17:26), but geographic isolation and other factors would have contributed to specific qualities we know today, especially after the flood.

Noahs' three sons were Shem, Ham and Japeth. Ham's son was Cush (Genesis 10:6+32).

His discendants, the Cushites (or Ethiopians), eventually settled in the area of Africa & Arabia.(The Greek Word for Ethiopian (Aithiops) means "Burntface."A Greek-English Lexicon, compiled by LidDELL and Scott (1948 )

Another AnswerThe first modern humans were undoubtedly black skinned, but they lived over a hundred thousand years ago. We could not possibly know who was the first black man on earth.