Blue is a pokemon trainer from the pokemon games, character in the pokmon adventures manga (pokespe) and populair fan image.
in the games...
Blue's concept art (Red/Blue/Green)
GEN 1 Although Blue (AKA: Leaf) was planned for the first set of games, red, green, blue and yellow, due to cartrige space, she was left out. This led to speculation over her name, as the rival took the name of Green (in Japan) and Blue (outside Japan. GEN 3
Leaf (pokemon XD)
In 2005, Nintendo drew up a new character based on the artwork of Blue from "pokemon adventures" manga...