Angela Kelly Ice Blue and Navy Trim Outfit

This is on the whole a rather unusual outfit for Her Majesty, comprised of a collarless coat and dress in the palest ice blue silk, with a contrasting navy floral trim. The hat, another Angela Kelly creation, is a navy blue upturned brim and floral trim and an ice blue straw crown.
It was first worn on 28 October 2011, the first day of the 22nd Commonwealth Heads of Government Meeting in Perth, Western Australia. The Queen wore a rarely seen brooch belonging to her mother, in the shape of a sapphire and diamond studded flower:

 

After a long stretch in the royal closet, the dress reappeared, worn on its own to an audience at Buckingham Palace on 16 October 2013 with Mr Andris Teikmanis, the Ambassador from Latvia. The Boucheron clips were worn (note the navy floral trim on the cuffs and hem, echoing that on the coat):

 

The following year, the whole outfit resurfaced on 15 June 2014, worn to Trooping the Colour, with the traditionally used Household Cavalry badge: