When you're a member of the British royal family, there are certain aspects of your life that are, for the most part, out of your control. They're expected to behave according to strict traditional rules that have been around for decades.
For instance, royal women are only permitted to wear natural nail polish colors when attending official events. This is why you never see Kate, the Duchess of Cambridge or Queen Elizabeth II wear bright-colored polish. In fact, the Queen has been wearing Essie's Ballet Slippers shade since 1989, and according to the company, "it's the only color Her Majesty would wear."
Other aspects of their appearance, such as hairstyle, are also under constant watch, which is probably why you never see a royal with an unnatural hair color. Perhaps, this is the reason why everyone goes bananas whenever Kate switches up her hairdo.
However, she's far from being the only royal who has opted for a drastic change. Her late mother-in-law, Princess Diana, also chopped off her locks back in 1990, and caused quite the stir when she debuted her rebellious new look.
The people's princess's former hairstylist, Sam McKnight, recently penned a book titled Hair by Sam McKnight, and in one of the chapters, he reveals the real story behind Diana's iconic short hair cut.