Queen Silvia, Prince Carl Philip, Crown Princess Victoria and Prince Daniel represented the Swedish Royal Family at this event. Queen Silvia wore a small purple cocktail hat with silk flowers and veil trim made by Swedish milliner Mode Rosa. It was a fantastic colour on her although I think I prefer her in full-sized hats, not mini ones.
Crown Princess Victoria wore a flowered, netted, voluminous cream and beige fascinator that I can only imagine would work at a wedding or a garden party. While I prefer Victoria in more colour, I really liked this dramatic hat (I suspect, made by Melinda Damgaard) on her.
Photos from Getty as indicated