Ink is an attack effect introduced in Super Smash Bros. Ultimate. It is a primarily used to make all fighters, some assist trophies and the floor look like they are covered in ink after coming in contact with moves that use the effect. The effect uses nine colors depending on what character is being used. Each of Inkling's alternate costumes has a different color (in order of orange, blue, yellow, green, pink, cyan, purple or indigo). After using Inhale, Kirby will use the color ordered after the Inkling opponent. The same is true for Ditto. Master Hand uses an exclusive aqua blue color for the Ink Blob attack. The color will change to pink if the cyan Inkling is fighting Master Hand in World of Light. Fighters and assist trophies will progressively get more ink on them if they are quickly hit with several attacks that use the effect. The effect is purely aesthetic and will eventually disappear if no ink is used for a while.
The effect is based on ink's functionality in Splatoon, which hinders the opposition's movement while traversing on enemy ink as well as causing damage to them (something that does not happen in Ultimate while the opponent is covered in ink).
List of attacks that use the ink effect
By enemies and bosses