The Tzemach tzedek in his "Divrei Elokim Chaim" quotes the Midrash that in the Messianic Age the curse of Noah will be fully implemented on the Bnei Cham, and that there will be no Hamites alive after Moshaich comes i.e. all the descendants of Cham will not be present, including Negroes, Chinese, Japanese, Koreans etc i.e most of pigmented humanity!