Why Princess Kate's revolutionary red nails weren't her first rule-breaking moment

The Princess of Wales is the golden girl of the royal family. Beloved by all and always perfectly primed and polished for any occasion, the mother-of-three is a beacon of elegance. Yet did you know that she doesn't necessarily always do things by the book? That's right, even the most respectful of royals love a subtle rule break or two, including Princess Kate…

The glamorous royal is known to experiment with colour in the wardrobe department, but her creativity also extends to her beauty routine. Princess Kate couldn't resist a red pedicure back in 2017 when she and husband Prince William enjoyed a royal tour of Germany – a beauty choice that seemingly departed from royal protocol.

Why? Allegedly, the late Queen Elizabeth II didn't allow for colourful nail polish. Royals are expected to keep their nails in pristine condition at all times and the go-to choice in Essie's royally-approved 'Ballet Slippers' shade. The classic tone, which costs only £7.99, is apparently the favourite hue royal ladies opt for when getting their nails manicured.

Unless of course, you’re Princess Kate, who has shown off a crimson pedi on several occasions, spanning sun-drenched summer outings to smart Easter Sunday affairs.

Perhaps the royal's red nail choice was a subtle nod to her late mother-in-law Princess Diana, another royal who had a penchant for playful nails.

Most notably, the People's Princess debuted a fiery red manicure as she stepped put in her iconic 'revenge dress' back in June 1994. The royal made a last-minute yet legendary outfit change before she attended a Vanity Fair party at the Serpentine Gallery, assembling one of the most famous looks in the grand canon of fashion history.

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SEE: 5 of Princess Diana's most show-stopping fashion moments

Princess Eugenie is another royal who is never afraid to push the boundaries of beauty protocol. The expecting mother has shown royal fans her rebellious side through her beauty choices, which so far have flown quietly under the radar. From Union Jack designs to classic red French tips, festive reindeer nail art to midnight black, Eugenie's eclectic nails take it even further than the current and former Princesses of Wales and their fabulous nails.