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:

Karl Ludwig Navy Honeycomb Coat and Rose Print Dress, Angela Kelly Straw Hat

This outfit sees an interesting change, as Her Majesty chose to have a different colour silk bloom placed in her hat to wear on different occasions.

The first appearance of this look was on 21 October 2014, when the Queen, along with other members of the Royal Family, welcomed the President of Singapore, Tony Tan Keng Yam and his wife to Britain for the first ever official visit to the UK by a Singaporean President.
The Queen chose this navy blue honeycomb coat with shawl collar and silk dress with a pink roses print on navy blue background, both by Karl Ludwig Couture, topped off with a navy straw creation by Angela Kelly, trimmed with a large pink silk rose to match the print of the dress. For this first appearance in this outfit, the Queen accessorized with one of Queen Victoria's diamond bow brooches:

A look at the dress:

The Queen repeated this look on 10 May 2015, for a Service of Thanksgiving at Westminster Abbey to mark the 70th anniversary of Victory in Europe (link to the Daily Mail article here). For this more sombre occasion, the Queen opted to have the pink rose in her hat swapped in favour of more muted white blooms, in the form of two silk lilies.

 

 

Sorry, I simply couldn't resist the Alice in Wonderland reference! ;)

 

The Queen wore the Cullinan V brooch: