All eyes were on Meghan Markle. Accompanied by husband Prince Harry, the Duchess of Sussex attended a private Netflix Beef Season 2 tastemaker event in Montecito, Calif., wearing a striking $715 chartreuse dress by designer Heidi Merrick paired with brown leather Jimmy Choo sandals. The look stood out against a crowd of attendees mostly dressed in black and white, sparking conversations about royal style etiquette. A former royal butler is now weighing in, suggesting the American duchess "broke Kate Middleton's rule" - unwritten guidance he says has long been followed by senior royals.