What were Pokémon Red and Blue called outside Japan?

Outside Japan, the first paired Pokémon releases were called Pokémon Red and Blue.

Japan originally received Pocket Monsters Red and Green in 1996, followed by a Blue version. For international markets, the Blue version’s updated code, artwork, and script formed the basis of the localized pair, which became Pokémon Red and Blue. The Japanese Green version was not released internationally in its original form.

The two versions shared the same main story and Kanto setting, but each contained version-exclusive Pokémon. That design encouraged players to trade through the Game Link Cable. The need to exchange Pokémon became one of the defining ideas of the series.

Pokémon Yellow followed as an enhanced edition inspired partly by the anime. It placed Pikachu in the starter role and changed several character and story details. Yellow was therefore a later special edition, not one half of the original international pair.