Since officially joining the royal family in 2011, Kate Middleton has largely followed royal rules. She rarely puts a wrong foot forward regarding her public looks. Although often compared to Princess Diana, Kate has rejected one of her late mother-in-law’s most iconic fashion choices.

Kate Middleton and Princess Diana significantly differ on one royal fashion rule

From the moment Princess Diana stepped out as then-Prince Charles’ fiancée, she appeared to have her ideas regarding royal fashion. Despite the palace’s longstanding traditions, Diana was ready to rip the royal rulebook and blaze her path.

On March 9, 1981, Princess Diana made her first official appearance with Prince Charles after their engagement announcement. The event was a charity gala at Goldsmiths’ Hall in London, and Diana wore a low-cut, stunning black gown.

David and Elizabeth Emanuel designed Diana’s look. The dress was notable not only for its dramatic style but also because, at the time, it was considered unconventional for a royal fiancée to wear black, a color traditionally associated with mourning.

“It was astounding,” Elizabeth Emanuel told British Vogue of the stir Diana caused by wearing that gown. “We witnessed the birth of a fashion icon before our very eyes.”

In contrast, Kate Middleton never wears black, deferring to the unspoken royal family rule. She does not wear the color to royal engagements and, instead, relies on a wardrobe entirely of rainbow-hued clothing and chic neutrals.

Kate Middleton refused to wear black even when under pressure

Kate Middleton wears dark green instead of black to the 2018 BAFTA awards | Samir Hussein/WireImage

Kate Middleton expresses her neutrality when dressing, even when under public pressure. One case in point was the 2018 BAFTA Awards, where women wore black to stand in solidarity with the Time’s Up initiative.

For that event, Kate stuck to the royal rule of refraining from wearing the hue. She arrived at the BAFTAs wearing a dark green Jenny Packham dress.

If she had opted to wear a black frock, Kate would have expressed a political position on behalf of Kensington Palace. However, she did sneak in some understated black accessories to her look, including a black belt, clutch, and heels.

The royals usually refrain from making public political demonstrations. Their rule is to remain neutral in all circumstances, even when dressing for an event.

Did Princess Diana wear black often?

Princess Diana appeared to refrain from wearing black to formal events after her first engagement event, where she was photographed alongside the late Princess Grace of Monaco. However, there were a few moments when she wore black during the later years of her marriage to then-Prince Charles.

Diana donned an evening gown by Bruce Oldfield for a performance of the play Les Misérables. In 1989, the Princess of Wales wore black velvet for the film premiere of Dangerous Liaisons.

Diana began wearing black more regularly once she separated from Charles. The people’s princess famously donned a Christina Stambolian dress to the Serpentine Gallery’s summer party in June 1994, widely known as Diana’s “revenge dress.”

Diana subsequently wore a Versace tank dress in September 1995 and a Jacques Azagury gown two months later. In 1997, she donned another one of Azagury’s designs, a sparkling floor-length number.