For her first formal introduction to the world on Nov. 16, 2010, Kate needed to find the perfect look -- and boy did she nail it! She rocks a refined Issa wrap dress (which sold out within hours of her appearance!) as she and Prince William announce their engagement at St. James Palace in London. Style bonus? The dark-blue color perfectly complements Kate's sapphire and diamond engagement ring, which once belonged to her fiance's mother, Princess Diana.