reference

炎攻撃の(ファイア)レッド、
草攻撃の(リーフ)グリーン…か‼︎

Fire-type attacker (Fire) Red,
Grass-type attacker (Leaf) Green... huh!!

from『pokemon adventures』Chapter 5 Episode 288.Title recovery that occurred when Red_(pokemon) and Blue_(pokemon) exchanged each other's Pokémon.

Pokémon FireRed and LeafGreen (ポケットモンスター ファイアレッド・リーフグリーン) title drop.

The first Pokémon was released as "Pokémon Red and Green" (ポケットモンスター赤・緑)in Japan ,and "Pokémon Red, Blue" in English-speaking countries. The characters' names have also been changed accordingly, and the English version does not tie back to the title.