The Queen does love to pull out a variation on lime, or citrus. It looked more like a lemon hue on TV, but in photos it’s more key lime. That green was her birthday color in 2016; she wore it at the Trooping the Color, and two months earlier when she turned 90 in Windsor, she wore a lighter tweedy suit in green. So she must have an affinity for it, and Harry IS apparently her favorite grandson, so that tracks. Anyway, she looked lovely, Camilla looked crazy, and Beatrice looked… lower-key, but not entirely sane.