Bisou Bisou is a sky blue to baby pink thermal nail polish that changes color based on temperature. This polish changes to sky blue when cold and transitions to baby pink when warm. The precious minutes before practice starts are important for performers. Sure, they need to stretch and warm up. But really, it’s a chance to gossip about last night’s show and whisper names for the next leading role. Please note that thermal polishes dry to a matte finish. We recommend applying our Looking Glass Top Coat for a glossy shine (don't worry it won't affect the thermal effecting). Store polish in a cool, dark place.