This is how Gaston costumes have changed over the years in the parks and various Disney On Ice shows.
Gaston had green pants, black boots, a red or yellow ascot around his neck and yellow or dark brown gloves.
1991-2005: Gaston had black or gray pants, a black belt, brown boots, a red ascot around his neck and yellow gloves like in Beauty and the Beast Live On Stage.
1991-present: This costume is same like the original but he has muscles and his belt is gold. This costume is only used in Beauty and the Beast Live On Stage.
1992-2014: This Gaston costume is only used in Disneyland Paris.
Gaston's pants, belt and boots are now brown, his gloves are a lighter brown and he no longer wears an ascot around his neck, looking closer to how he appears in the film.
DOI 2012-Present: This version of Gaston is the closest match to his animated version.