Moses married an Ethiopian, who was in all probability black.
The Hebrews were under restrictions concerning conditions like being Jewish but not by race.
Yes, Moses was involved in an ethnically adulterous affair, an illegitimate marriage to an Ethiopian woman, that both Miriam and Aaron (Moses' brother and sister) condemned and Miriam got into trouble for her insubordination.
It's telling that the Bible doesn't even name the illegitimate Ethiopian wife, but it does reveal Moses undoubtedly put her away, had no children by her, and properly married a White Midianite woman, whose name the Bible mentions (Zipporah), the mother of his sons.
The Hebrews, forefathers of British-Israelites and Jews, were instructed against interracial and interfaith folly, and the two often went hand in hand (no pun intended).