Costume

Color changes, or Tints is a new feature to the Smash Flash series. It is planned to run similarly to the Super Smash Bros. costume changes. It's possible that some tints can make your character resemble other characters in their universe.

In Super Smash Flash
There wasn't option to change a character's color in Super Smash Flash.

In Super Smash Flash 2
In Super Smash Flash 2, the player may choose to add a tint to their character based on the team of the individual character, from only red, blue or green (for now), possibly Purple, Orange, Yellow, Dark and White will appear. To the disapointment of many people, costumes are not used because they would increase the file size dramatically. Evilgram developed a piece of code which would have supposedly allowed the use of costumes via replacing the colors of already existing sprites, but it turned out either the code wasn't able to do so or Cleod9 was not able to utilize it. The closest way a character can change color is when it's a team battle. The characters will have a tint of whatever team color they are part of.