Color changing nail polish is a kind of nail polish that changes in color when it is exposed either to sunlight or changes in temperature. It is generally considered to be a trendy kind of nail polish and, as such, it is common for color changing nail polish to appear in trendy rather than classic colors. Although there are a few kinds of color changing nail polish that change between classic colors such as pink and ivory, most kinds change between colors like royal blue, magenta, kelly green, and yellow. It is most common for color changing nail polish to change only between two colors: the color that appears on the nail when it is first applied and the color that it changes to when it is exposed to heat or sunlight.

In most cases, color changing nail polish has the ability to change back and forth between two colors. Instead of simply changing once, upon contact with heat or with direct sunlight, the nail polish will return to its original color when it is no longer in direct sunlight or when it comes into contact with cooler temperatures. The change in colors in this kind of nail polish is much like the change in color in a mood ring.

This kind of nail polish is not nearly as popular as regular nail polish that does not change colors. Part of this may have to do with the fact that many people prefer to wear more traditional colors, especially as there are a number of professional settings in which wild nail polish colors such as peacock blue and neon orange are not acceptable. There are a number of beauty supply retailers and even some well-stocked pharmacies and drug stores that do sell color changing nail polish. Additionally, there are some salons that include color changing nail polish among the array of polishes that can be chosen for manicures and pedicures.

Color changing nail polish is usually slightly more expensive than regular nail polish, though the difference in price is not exorbitant. Whereas a bottle of regular nail polish might cost a few US Dollars (USD), a bottle of color changing nail polish is likely to cost a few USD more. Some pricier brands can cost double what regular polish costs per bottle.