Kate Middleton is known for her elegant style, and the Duchess is often seen as a trendsetter when it comes to her fashion sense.
However, like most things within the royal family, strict protocols and rules are to be followed for almost every occasion.
One traditional royal rule, however, seems to have been broken by Kate.
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The Duchess of Cambridge's style resembles a true princess when it comes to her colourful coats and tailored dresses, but her influence comes with a number of royal rules to follow, which isn't always easy when you're constantly in the public eye.
Despite a litany of rules, it appears that Kate is not one to play by the book and has been spotted breaking royal protocols and 'disrobing' in public a number of times when attending events, according to the Express.
Marketing Manager at jewellerybox Daena Borrowman said: "There are dozens of protocols in place that stylists and dressers of the royals have to familiarise themselves with". That is, so working royals represent the Queen and the country in the best light when on public outings.
Daena revealed to Express.co.uk one of the most essential style rules. She said: "Royal women are expected to keep their coats on at social events".
This is because "disrobing in public is perceived as distasteful according to royal protocol," the expert explained. Therefore, royals are not supposed to take off their coats or jackets in public, ever.
Daena said this would explain "why so many royal women prefer coat dresses". In fact, the Duchess of Cambridge favours coat dresses and has been seen wearing them on many occasions.
However, the style expert explained she had been spotted breaking this royal rule before.
Daena explained: "More recently, the Duchess of Cambridge has bent this rule and taken off her coat whilst attending indoor events."
Other important royal style rules have to do with the colours members of the Royal Family choose to wear when travelling abroad.
The expert said: "Whilst touring abroad, royal protocol dictates that royal women also honour local history and traditions by sporting the colours of the country they are in."
They can also do so by "wearing jewellery gifted to the Queen by that country or respecting local customs such as covering the head with a scarf".
Daena also said that all royals, and especially Her Majesty, are meant to be "easily distinguishable in a crowd".
This is why "the Queen favours bold colours and prescribes them to her family". It is believed one of Her Majesty's favourite outfit colours is lime green.
The Queen has worn that shade on the most memorable days, such as her 90th birthday in 2016. Lime green is the perfect colour to stand out from the crowd, but it is believed she loves green in particular as it represents hope.
The fashion expert also explained why royals always carry a black outfit when travelling. "A tragedy delivered a life lesson, giving rise to a whole new travel protocol that applies to this date," she said.
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