Princess Kate Middleton is back to brunette. The Princess of Wales stepped out with her husband, Prince William, on Monday, September 8, with her signature brown hair after surprising royal watchers with blonde locks last week. The couple took a trip to Sunningdale on Monday to celebrate the memory of Queen Elizabeth II on the third anniversary of her death. For the outing, Kate, 43, stunned in a plaid outfit with her long brown hair curled while she and William, also 43, visited the National Federation of Women's Institute, a cause the late queen supported prior to her death.