UV Changing Nail Polish Is The New Way To Brighten Up Your Next Mani

Mood rings took off in the mid-'70s during the tail end of the Vietnam War. By the late '90s and 2000s, these color-changing rings were predominately worn by middle schoolers and paired with boot-cut jeans and graphic tees from the Delia's catalog. As evidenced by social media trends and today's most popular storefronts, modern "mood jewelry" has expanded to include bracelets, necklaces, and classy rings you can wear without feeling too much like a fifth grader. It's official: emoting is back in style.

In recent years, high fashion brands like PH5 have taken the mood ring approach when it comes to clothing. For instance, the viral UV-reactive dress — which transforms from white to pink in the sunlight — opened up a world of multichromatic possibilities when it comes to our wardrobes. Now, color-changing nail polish is taking the beauty world by storm. Here's what you need to know about this newest high-tech nail craze and how to get your manicure to change from purple to blue and back again.

In a TikTok with nearly 2 million views, the Kiara Sky Nails account demonstrates how their color-changing gel polish can switch back and forth between light and dark purples, blues, and pinks when submerged in a bath of ice-cold water. These are thermal nails, meaning that changes in environment or body temperature will set off a very fashionable chemical reaction thanks to one key component: leuco dye. Although the vast majority of thermal polishes have just two color options, a select few brands offer a broader spectrum. KBShimmer, for instance, sells tri-thermal purple, green, and blue paint.

Whereas venturing into an air-conditioned store or jumping into a cold lake in the summertime can trigger a thermal reaction à la mood rings, other nail polishes (much like the viral PH5 dress) react to UV rays. This is called photochromism. The vegan and cruelty-free nail polish brand LivOliv explains that the same effect is used for transition lenses. So brighten up your next at-home or salon mani by opting for thermal French tips, polka dots, or pay homage to the '70s with a vintage swirl pattern.

Nail polish is far from the only color-changing beauty product on the market. You may have seen the viral "green" blush from Youthforia or those lip balms that magically change from clear to pink upon contact with the skin. But how do they work? Whereas most nail polish formulas change color as they react to temperature or sunlight, lipstick and blush products will respond to your skin's pH (potential hydrogen).

Cosmetic chemist Javon Ford outlines the process for PopSugar, noting, "pH makeup uses a class of colors called bromo acid dyes that basically function like pH indicators or litmus paper." However, since most people don't fall above 5.5 on the pH scale, the vast majority of reactions will result in a similar pinkish-red color.

According to TikTok creator Kali Ledger (@kali.ledger), Youthforia's green blush — which retails for $36 — is perfect if you're trying to achieve that sun-kissed natural look. But keep in mind that the color may vary depending on the pH levels in your foundation.