You've all probably heard by now of mood nail polish, but if there's anyone who doesn't, it's polish that changes color based on temperature. I bought 2 from Claire's, one called happy/earthy (the green/yellow one) and one called fabulous/funky (dark/light pink). Here's an example of the green one:
I absolutely love this polish! If your nails are long enough like mine, you can see the color change even at room temperature, without doing the hot or cold water thing. But here it is in hot water then in cold just to show you guys:
This next picture is without any hot or cold water, I was just really cold sitting in my room for a few hours and here's what my nails looked like.
I'll probably do a swatch of the pink one I bought at a later time, but for a heads up, either I got a faulty bottle or it really doesn't change color AT ALL.