Kate Middleton and husband Prince William are currently in Sweden, as part of their royal tour of Norway and Sweden.
The Duke and Duchess’ first official engagement was at a Bandy hockey match in Stockholm, where the pregnant royal, 36, dressed in an all black outfit.
Wearing a pair of Sorel boots, a black Burberry coat and black jeans, Prince George and Princess Charlotte’s mum totally disregarded the royal no all-black rule.
Royals are not expected to wear all black to events for several reasons, including the fact they’re usually saved for Remembrance Day and funerals.
According to Marie Claire, all black outfits are usually saved for sombre and commemorative events.
For example, when the royals travel they must always back a black outfit with them incase there is an unexpected death.
Pregnant Kate Middleton and Prince William embark on royal tour of Sweden and Norway [Getty]
Another reason Royals usually don’t wear all black is because they don’t stand out in the crowds.
The Queen, for example, will always dress in the brightest of colours to ensure the fans and public can see her at an event.
The countess Sophie of Wessex once said: “Don’t forget that when she turns up somewhere, the crowds are two, three, four, ten, 15 deep, and someone wants to be able to say they saw a bit of the Queen’s hat as she went past.
“She needs to stand out for people to be able to say ‘I saw the Queen’.”
In a similar way, other royals such as Kate Middleton normally abide by this rule by dressing in bright orange shades, pinks or blues.
Kate’s all-black looks comes weeks after Meghan Markle did the same, and broke the royal fashion rule by stepping out in Wales in dark shades.
Find more details about Prince Harry’s bride-to-be’s controversial look here.