Why didn't I think of this before?! I first saw an ad for "Mood Polish" in my Glamour magazine so I had to check out their site! The varnish actually changes color! I'm not sure if it's really based off of your mood or the temperature around you, but it definitely seems worth a try! Unfortunately they only ship to the US, but if you're from here and interested, they sell for $8 a pop on their site, which you can check out here.