The American Poultry Association recognizes three colors of Brahma Bantams: Light, Dark, and Buff. The American Bantam Association recognizes five colors: Light, Dark, Buff, Black, and White. I've seen the Blacks and whites before and although they are much more uncommon, they will compete toe to toe with the other three colors. If they don't win at shows it is because judges are hesitant to place them because if it is an ABA and APA meet, then for the APA they can't go any better than best of variety, even though on the ABA side, technically they could win champion bantam.
David