A website URL has been registered for Pokémon Grey.
As spotted by Nintendo Buzz, the site was logged by Melbourne IT Digital Brand Services - the same outfit that set up pokemonblackwhite.com which is currently used by Nintendo of America.
Nintendo hasn't confirmed any plans for a third string to the Black/White bow, but it would come as no surprise. All core Pokémon titles have seen a third release appear about a year after launch.
In other Nintendo news, the platform holder is holding a 3DS webcast this friday, with new announcements promised. Seems like as good a time as any to lift the lid on a new Pokémon title.
Still, grey? Really?