Using a Rainbow-colored Snail Shell will transform you into a Red Snail... but you can't end the effect. Right clicking the ability on the upper right does not terminate the transformation. Exiting/logging back in does solve it, though. Literally. Unplayable.
Use items aren't buffs, so they can't be cancelled. That's intentional not a bug. Transform pots all have different durations, red snail probably has one too, just not sure what it is. Taking damage from monsters and relogging should cancel it.
Just to make sure we're talking about the same kind of use items, things like accuracy potions or attack potions are currently uncancelable. They were cancelable in the old source (rainbowcolored shell included) and I definitely think that they should be cancelable, since there are reasons to want to do so.
