I just fought the Elite Four and Bertha, the Ground-type user, had a black Hippowdon. According to the Psydex, the Pokemon isn't black when it's shiny. Could someone explain to me why it was black?
Please pay a bit more attention to the sticky threads from now on. As was stated below, the answer to your question is right on the front page.
"No progress ever came from war, only a false sense of increase."