I assume it comes from the misconception that all Africans are black. Egypt has always been ethnically diverse - and anyway, Cleopatra was Greek. Plus, modern conceptions of race don't map on neatly to ancient times.
masculine list:
https://www.behindthename.com/pnl/191050/124079feminine list:
https://www.behindthename.com/pnl/191050/124080