A Corphish Out of Water

With a new Pokémon in tow, Ash continues his training to prepare for his rematch with Brawly. However, though caught, Corphish is still a ruffian as it introduced itself by whacking all the other Pokémon on the head. Can it ever be more social with other Pokémon, and why is Jessie's Silcoon purple right after it evolved?