Which Splatfest-only Splatoon 3 mode features the Ultra Signal?

The Splatfest-only Splatoon 3 mode featuring the Ultra Signal is Tricolor Turf War. It changes the usual four-versus-four Turf War into a three-team contest with one defending team and two attacking teams.

The Ultra Signal appears in the center of the stage. The defending team tries to protect it, while the two attacking teams attempt to claim it. If an attacker succeeds, a Sprinkler of Doom is created for that side, continuously spreading its ink and helping it cover the map.

Tricolor Turf War was introduced in Splatoon 3 as a special variation of Turf War during Splatfests. Early on, players entered through regular Turf War and could be selected for a Tricolor match; later changes made the mode more directly selectable during relevant Splatfest periods.

The other options are standard competitive or cooperative modes. Clam Blitz uses clams and a goal basket, Tower Control revolves around escorting a tower, and Salmon Run is a cooperative battle against Salmonids.