From Bulbapedia, the community-driven Pokémon encyclopedia.
Colosseum Leader Rosie (Japanese: Rapura) is the fourth Colosseum Leader in Pokémon Battle Revolution. She is the head of Neon Colosseum. Similar to other Leaders in Battle Revolution, her costume resembles a Pokemon. Her costume of choice is a Roserade. She has white hair, black skin, and dark red eyes. Her design is based on the "Cool Girl" Model.
Interestingly enough, Rosie is the first black character in Pokémon.