Kate Middleton Rarely Breaks This Traditional Royal Accessory Rule

It's no surprise that the rules the British royal family abide by dictate their manner of dress. No matter how outdated some royal rules and protocols seem, regulating people's style helps the British royal family look poised and united. Catherine, Princess of Wales, started breaking some of these fashion rules as soon as she married into the family. She opted to wear her hair down on her wedding day, with only a few strands pulled back, instead of sticking to the traditional updo. Throughout the years, she also chose to wear skirts slightly above the knee and not wear skin-tone tights for every occasion. 

However, Kate Middleton is pretty good about following one particular accessory rule: no hats at night for women. King Charles III's former butler Grant Harrold told Hello! how, "There was a rule that stated ladies could wear hats from the morning at 6 a.m. until 6 p.m. After this, they would wear tiaras if they were married." He added that Queen Camilla and Kate don't wear hats as often as the late Queen Elizabeth II did, but they abide by the rule on formal occasions. 

Although Kate doesn't wear hats too often, she does a decent job at remembering to take them off in the evening. However, despite her marital status, she doesn't wear tiaras for all nighttime events; she seemingly saves the bling for big events like state dinners.

Royal fashion rules have a say on when individuals can wear certain items, such as hats, as well as the styles they should avoid or reserve for specific occasions. For instance, senior British royals are only supposed to wear black at funerals and during mourning periods, and on holidays commemorating military battles. It was pretty dramatic to break this rule in the past with Princess Diana's revenge dress being a famous example. 

Catherine, Princess of Wales, usually favors bright, rich colors, and she often avoids wearing black when it's not warranted. In February 2026, Kate Middleton wore a chocolate brown outfit in London ahead of her visit with Sarah Mullally, the first female Archbishop of Canterbury. Kate wore a monochrome olive-green outfit the previous October at a visit to a nonprofit in Oxford, England. In December 2025, she and other senior royals welcomed German President Frank-Walter Steinmeier on his state visit to England. As seen above, Kate was technically wearing a black top or dress, but it was covered by a long, blue McQueen coat and was probably considered more acceptable than wearing an all-black outfit.

Wpa Pool/Getty

Despite the consistent effort to wear color, the Princess of Wales has worn black outside of a somber event. For instance, she wore a stunning, all-black velvet dress for The Sun's Military Awards in 2011. The only pops of color in her outfit were the pinkish-red gems in her necklace and bracelet. For a look this good, bending the rules was well worth it.