Cushites - Southern Hamitic Tribe, Darkest Skinned

Also known as Ethiopians, "Cushite" is an obscure word that is generally believed to mean "dark". Jeremiah 13:23 seems to confirm that this is in connection with the tribes' constrasting skin color by rehtorically asking, "Can the Ethiopian change his skin, or the leopard his spots?". 

Ethiopia simply means "black".