Powder Pink Patterned Coat, Petunia Print Dress and Rachel Trevor Morgan Hat

This look is comprised of a delicately patterned powder pink collarless coat with flap pockets, a silk dress in a dark pink petunia print and a delightful pink straw hat by Rachel Trevor Morgan, trimmed with an oversized peony blossom and looped bows to one side.
It was debuted on 18 June 2013, Day 1 of the Royal Ascot races. The Queen accessorized with her multi-coloured diamond floral brooch:

It was repeated the a year later, on 25 June 2014, to a garden party at Hillsborough Castle, Belfast, Northern Ireland. This time the Queen chose a not-often-seen brooch, a stunning pearl and diamond piece which was part of the parure Princess Alexandra received as a wedding gift from her husband-to-be Albert Edward, Prince of Wales in 1863:

 

The look was repeated on 22 June 2016 when the Queen undertook a series of engagements in Liverpool, including a visit to Alder Hey Children's Hospital (Daily Mail article here). She wore her Pearl Trefoil brooch: