Nefertiti was not a black African, although her husband, the Pharaoh Akhenaten and his mother, the Queen Tiye, do appear to have had a least the possibility of some black ancestry.
Most of Ancient Egypt's pharaohs over the thousands of years of that empire, were not primarily black African, but mostly Mediterranean in ethnic/racial background.
There was a dynasty of black pharaohs during a period when Nubia/Kush controlled Egypt.
All that being said, the ancient world did not have the racist attitudes that much of the world's population has today, so, although royal families may still have tended to marry within their own extended family groups (and even married brothers to sisters), taking a wife or concubine from another racial or ethnic group wouldn't have been forbidden on the basis of race alone.
Take a look at the first links below that show images of Nefertiti, Akhenaten, and Tiye. The other links are to info about the black/Mediterranean ancient Egyptian theories. Snowden's are premier, IMO, as that was his specialty area of study and he was a very well-respected African-American professor at Howard University.