The Infinite Boost is an ability for Sonic exclusive to the Nintendo DSversion of Sonic Colors. An skill unusable to the player from the beginning of the game, it can be unlocked by collecting all the Special Rings in the game. After that, the Infinite Boost can be activated (or deactivated) in the "Options" menu.
In gameplay, the Infinite Boost allows the player to use the Boost without its duration being restrained by the Boost Gauge's remaining energy. As such, the player can perform the Boost for as long as they like without worrying that it will come to a stop from running out of energy. However, the Boost Gauge will still be drained while the Boost is in effect. Regardless, even if the Boost Gauge is completely drained, the player can still perform the Boost. In addition, the Boost Gauge will rapidly recharge itself on its own between every usage of the Boost.
The Infinite Boost is only usable in the "Play Game" scenario; that means it is not applied to the gameplay in the game's Time Attack and Versus Mode.