Ah, that Kip Calculator and those books!!!
       A couple of years ago Chicken Street and someone else who's name escapes me showed pictures of both Black X Buff and Splash X Buff Orps.                 Though E is said to be dominant to eWh the Buff Orp has such a powerful artillery of genes that cause it to be buff that the result is in fact predominantly buff birds with coloured tails.
                  It is one of those sad, and to me immensely disappointing, facts that so much of the information in learned texts is just regurgitated twaddle from earlier writers that has never been retested and is in fact wrong.