Watch: Kate Middleton Is Officially a Blonde After Major Hair TransformationPrincess Diana's hairstylist is celebrating Kate Middleton's blonde ambition After the 43-year-old debuted her lightest hairstyle yet, Sam McKnight, who served as Diana's personal stylist until her 1997 death, wasted no time brushing off Kate's haters. "I am shocked, horrified, and dismayed by all the nasty comments about the Princess of Wales today," he wrote on Instagram Sept. 4. "A woman's hair is very personal to her, it's armour, defence, confidence and so much more.