When these games proved popular, an enhanced Blue version was released sometime after, and the Blue version was reprogrammed as Pokémon Red and Blue for international release. The original Green version was not released outside Japan.[citation needed] Afterwards, a second enhanced remake, Pokémon Yellow, was released to use the color palette of the Game Boy Color and more of a stylistic resemblance to the popular Pokémon anime. This first generation of games introduced the original 151 species of Pokémon (in National Pokédex order, encompassing all Pokémon from Bulbasaur to Mew), as well as the basic game concepts of capturing, training, battling and trading Pokémon with both computer and human players.