Kate Middleton, the 41-year-old Princess of Wales, created a stir with her eye-catching Easter fashion choice, one that the late Queen Elizabeth II might have disapproved of. Attending church service with her family, including her husband Prince William, and their three children, Prince George, Princess Charlotte, and Prince Louis, Middleton made a bold statement with her bright red manicure.

The royal family appeared in matching blue outfits, with Middleton wearing an electric-blue Catherine Walker coat dress. However, her red manicure stood out against her blue clutch, as reported by People. This choice deviated from the Princess' usual neutral, nude, or clear nails and seemingly went against the late Queen Elizabeth II's "unofficial rule" concerning nail color during royal events.

While no official rule dictates the nail color for British royal family members, a general guideline exists. "There's no actual protocol about dark nail polish," royal correspondent Omid Scobie told Harper's Bazaar in 2018. "It's simply about being appropriate."

Queen Elizabeth II reportedly found colorful nail polish distracting, and though not officially prohibited, she preferred more practical nude colors for official engagements, according to People. The late monarch frequently wore a neutral nail polish shade, Essie's "Ballet Slippers."

In 1989, the Queen's hair stylist informed Essie Weingarten, the brand's founder, that the sheer pink polish was "the only color Her Majesty would wear," as stated on the brand's official website.

However, Middleton is not the first royal to break the unofficial nail polish protocol. In December 2018, Meghan Markle sported black nail polish to match her one-shoulder gown at the British Fashion Awards. The Duchess of Sussex was pregnant with her son Archie, whom she shares with Prince Harry, when she presented the award for British womenswear designer of the year to her wedding dress designer, Clare Waight Keller.

After being named Princess of Wales following Queen Elizabeth's passing in September last year, Middleton seemingly began a new fashion era, leaving behind her long polka-dot dresses. In October 2022, she wore a bright yellow belted dress at an official event at the Royal Surrey County Hospital's maternity unit. The following month, she appeared in a bright red Alexander McQueen coat over a burgundy turtleneck top, paired with brown suede boots, at a rugby match between England and Papua New Guinea.

Prior to Sunday's Easter service, Middleton sported a Catherine Walker teal coat dress, hat, and heels, along with a Cartier shamrock brooch, on St. Patrick's Day.

The British royal family is preparing for King Charles III's coronation at Westminster Abbey in London on May 6. The Waleses are expected to attend, while Prince Harry and Markle have not yet confirmed their attendance.