“It’ll be the dress that will be the most talked about, it will be analysed in every detail,” said Caroline Young, a writer specialising in fashion.

While the design of Camilla’s gown is being kept under wraps, the 75-year-old queen consort commissioned British couturier Bruce Oldfield, who boasts a long list of high-profile clients, including Charles’s ex-wife Princess Diana.

According to fashion expert and royals’ commentator Miranda Holder, the coronation gown is going to “define” Camilla.

“It’s going to go down in history,” she added.

Britain last held a coronation in 1953. Charles’s mother Queen Elizabeth II wore an intricately embroidered white satin gown on the day.

But Camilla is likely to opt for something less luxurious with the new king keen to slim down the ceremony as the country grapples with a cost of living crisis.

When the royal procession arrives at Westminster Abbey on Saturday, the queen will be cloaked in a crimson velvet “Robe of State”, originally made for Elizabeth 70 years ago.

‘Working with Diana’

Camilla will be crowned with Elizabeth’s grandmother Queen Mary’s Crown, which she wore at the coronation of her husband King George V in 1911.

In honour of Camilla’s late mother-in-law, the crown will be reset with several diamonds from her personal jewellery collection.

According to British media, Oldfield, 72, has designed Camilla’s gown but Buckingham Palace was keeping tight-lipped when contacted by AFP.

Oldfield designed dozens of evening gowns – several of them iconic – for Diana before her death in a Paris car crash in 1997.

“He was developing his own style and aesthetic while he was working with Diana,” Holder, the royal fashion commentator, said.

But after Diana’s formal separation from Charles in 1992, she distanced herself from royal life and the designer.

Oldfield had since become one of Camilla’s favourite fashion creators, as well as a long-time acquaintance.

He designed the elegant black evening gown Camilla wore on the royal couple’s state visit to Germany in March.

Glamour v confidence

“I gave Diana her glamour and Camilla her confidence,” Oldfield was quoted as saying in 2014.

While the outfits of heir to the throne Prince William’s wife Kate are some of the most scrutinised on the planet, Camilla’s style has often left commentators indifferent.

“I don’t think people kind of go, ‘wow, look at what she’s wearing!’ But I think she knows perfectly what is the right fit for the right occasion,” Young said.

According to Holder, Camilla likes pastel colours but also “flamboyant” jewellery.

“She is very earthy and natural in her spare time. She was in her 60s when she married prince Charles. It was a little bit of an advantage,” Holder added.

She said Camilla was not under the same “scrutiny” as Kate or Meghan, whose husband is Charles’s younger son Harry.

As for the design of the coronation gown, it’s a guessing game for now.

Holder predicts Camilla will be wearing blue or a “pastel colour”. But definitely not black.

‘Fantastic fashion’

“Black is a no-no. It’s for evening, red carpet,” Holder said.

The fashion expert also expects “much symbolism” that will reflect the Commonwealth nations and the countries making up the United Kingdom: England, Scotland, Wales and Northern Ireland.

Young says that Camilla will not want her outfit to be “too showy”.

“She’s got a difficult job because she’s been criticised for years and years as being the other woman,” Young said.

“So she has a reputation at stake as well,” she added.

The start of the king’s reign also comes as many Britons struggle with stubbornly high double-digit inflation.

“So there can be the worry that it might be criticised for being too ostentatious, too expensive. All that will be in her mind,” Young said.

But Holder hopes that cutting costs in other areas of the coronation will allow “to splash out on a bit of fantastic fashion”.