Alternate costume (SSB)
In Super Smash Bros., each character has at least four alternate costumes, one for each of the C Buttons used to select them. Some characters have an extra costume (or two) to accommodate Team Battles if their four selectable costumes lack a red, blue, or green variation; these particular colors cannot be selected outside of Team Battle.
The original Smash 64 website in Japan listed what each specific color was inspired by from previous Nintendo games and media prior to the release of the original game, along with some additional names for specific colors. These have been translated below and are considered to be official names for each alternate color, although there do exist some inconsistencies between the source material of the costume and the official explanation.
In Team Battles, if two identical characters share the same color scheme, the second player will have a lighter tint in their appearance. A third player uses a darker tint, which technically means that each character has 4 more costumes for Team Battles. A fourth player would appear the exact same way as the first player, though it is not possible to have four players on the same team through regular gameplay.
Due to the dark lighting of the formerly tournament-legal Congo Jungle, the Smash 64 Backroom recommended avoiding the use of certain grey or black costumes when the stage was in use. If such a costume was used on the stage, any players in the match could reset the match so that the offending player could select a different costume. In the lists below, these costumes are marked with a black "!" in the team column.