Mixing urgency with nobility and opulence, it’s the regal colour combo which puts lesser mortals in their place. No wonder the Royals are reaching for ‘PRED’…

Red asks to be seen. Being shy and retiring is not.

Next to red on the color wheel is purple, a shade with quite different connotations.

Purple also loves attention, but where red is urgent, purple is synonymous with nobility and opulence.

The dye was once so expensive that Elizabeth I is said to have reserved purple clothing for her immediate family, ensuring its exclusivity.

So wearing red and purple side by side is the fashion equivalent of wearing a flashing neon sign on your head that says 'look at me! I have something important to say!'

The purple and red (Pred) dress matched the pink carpet perfectly

Princess Diana at a dinner in Bangkok in February 1988, wearing a red and purple chiffon evening dress by Catherine Walker

The same Catherine Walker dress came out for an Aida performance in aid of The Prince's Trust in June 1988

The latest royal to embrace this color clash is Queen Maxima of the The Netherlandswho stepped out in Rotterdam to present the Cultural Fund Prize in a purple dress with embroidered red lace details.

As a pioneer as she was, Princess Diana was the first royal woman to harness the power of 'pred' (purple/red – hang in there).

Such a bold combination was a perfect fit for the theatrical, unapologetically dramatic silhouettes of '80s fashion.

A power shoulder not powerful enough? Make it a scarlet mailbox!

A kitty bow not gigantic enough? Make it violet!

For a banquet hosted by Crown Prince Maha of Thailand in 1988, Diana chose a red dress with purple shoulder detail by Catherine Walker, and it positively exuded regality – no small feat when you're surrounded by a plethora of international royals.

When Prince Charles arrived for a three-day tour of Hong Kong in 1989, a purple pencil skirt, cropped red jacket and purple booter with red trim were the order of the day. Such a bold clash of lush colors left one thing unequivocally clear: there was a princess in the building.

Princess Diana wore a purple pencil skirt, a short red jacket and a purple booter with red trim when she arrived in Hong Kong in 1989

Princess Diana again wore Catherine Walker's red and purple suit in Agra, India in 1992

Diana wearing purple and red at the Taj Mahal in 1992

In 1992, the same red and purple outfit took on a different meaning, when Diana wore it again for the now iconic photos of her sitting alone outside the Taj Mahal.

By then she had already divorced Charles, but the color combination still exuded something royal.

In fact, she was more regal than ever.

As her brother Earl Spencer said in her eulogy, “She didn't need a royal title to continue generating her particular brand of magic.”

Pred lay low in the '90s and '00s (it couldn't quite find its place next to the ripped jeans and plaid shirts of the grunge movement).

But it returned to the scene in a big way in January 2019, when the Duchess of Sussex wore a red coat over a purple dress for her first public engagement of the year.

Six months after her wedding and newly pregnant, the powerful color combination cemented her place in the public consciousness as part of the royal establishment.

It also served the practical purpose of making her and Harry visible to the huge crowd that had gathered to catch a glimpse of them. She may have been inspired by the late Queen, who had worn a purple coat and matching hat during a visit to Lincoln's Inn in London the month before, in December 2018.

A small glimpse of a red dress underneath the coat, plus a red feather poking out of her hat, made this the Queen's first official pred moment.

Meghan wears a purple and red combination to mark the 100th anniversary of Wilfred Owen's death in 2019

The Queen looks festive in her purple coat with a glimpse of the purple and red dress underneath on Christmas Day 2014

Red and purple for Queen Elizabeth II as she takes a video call during the pandemic in 2020

Lady Gabriella Windsor looks regal in a purple and red dress at a party in 2019

The fashion world ultimately capitalized on the power of this punchy colorway, with pred popping up all over the AW20 runways, especially at Saint Laurent and Bottega Veneta.

Once again, the late queen eschewed her usual one-block color uniform and wore a geometrically printed red and purple dress to receive the Order of St. John's first-ever Service Medal at Buckingham Palace on March 11, 2020.

Amid growing concerns about the coronavirus (the national lockdown began on March 23), the pred combination evoked a reassuring message of both power and serenity. Did you think clothing was little more than a practical measure against immodesty and hypothermia?

Pred proves that it's time to rethink that.