Kate Middleton nailed her Easter Sunday look.

To celebrate the holiday on April 9, the Princess of Wales wowed in an electrifying royal blue coat dress that she paired with an equally eye-catching manicure, as she painted her nails a bright cherry red. If anything, Kate's surprising style move marked the first time she's worn the crimson shade since marrying Prince William in 2011.

The 41-year-old—who typically sports neutral nail polish or none at all—completed her outfit with a matching blue clutch, fascinator hat, sapphire earrings and nude pumps. And she wasn't the only royal in blue either, as she twinned with her husband and their three kids Prince George, 9, Princess Charlotte, 7, and Prince Louis, 4, at the St. George's Chapel Easter service.

While there aren't any official rules about how British royal family members can paint their nails, it's believed they follow a general guideline.

"There's no actual protocol about dark nail polish," Omid Scobie, royal correspondent and Finding Freedom author told Harper's Bazaar in 2018. "It's simply about being appropriate."

The late Queen Elizabeth II was famously known for favoring Essie's pale pink polish "Ballet Slippers" and set the precedence for other royal women to wear light, natural hues on their nails.

In fact, Meghan Markle honored the monarch by sporting a manicure in "Ballet Slippers" hue for her wedding to Prince Harry. Kate, on the other hand, rocked the brand's pale shade in "Allure" for her big day.

In 2018, however, Meghan ignited a mini-scandal when she made a surprise appearance at the British Fashion Awards with dark nail polish. The former Suits star, who was pregnant with her and Harry's son Archie Harrison at the time, matched her mani to her body-hugging Givenchy gown.

But it's clear Kate is able to usher in a new fashion era among the British royal family with her recent bold, risk-taking attire. Case in point? For the 2023 BAFTA Film Awards Feb. 19, Kate turned heads in a white one-shoulder Alexander McQueen gown that she styled with black opera-length gloves. 

A week later she ruled the sidelines at the Wales vs. England Six Nations rugby match in a bright red and white houndstooth coat that paid homage to one of Princess Diana's most daring style moments. 

With King Charles III and Queen Camilla's May 6 coronation, it's only a matter of time before Kate reigns supreme with her fearless fashion.