Acid Green Karl Ludwig Suit and Philip Somerville Hat

This suit in a dull acid green pinstripe fabric with oversized jacket and silk cuffs and lapel by Karl Ludwig, plus straw Philip Somerville hat trimmed with a silk side bow was chosen for the Epsom Derby on 21 June 2002, paired with the Jardine Star brooch:

Then again for the opening of the newly-refurbished Ministry of Defence building in Whitehall, London, on 14 October 2004, accessorized with the Greville Ivy Leaf brooches:

 

 

 

Shimmering Brocade Suit in Bronze, Silver and Aqua

The Queen debuted this bronze, silver and aqua shimmering brocade outfit in a floral motif at a Commonwealth Day reception at Marlborough House in London on 14 March 2011. She accessorized with her six-petal diamond flower brooch:

 

 

She then repeated the look to a reception at Trinity House in London on 20 June 2011. The Corporation of Trinity House is one of Britain's oldest maritime organisations, having been formed under a Royal Charter given by Henry VIII in 1514. The Queen wore her Boucheron aquamarine and diamond clips:

 

 

The Queen wore this suit again for the London 2012 Paralympics Opening Ceremony on 29 August 2012. She accessorised the look once again with her Boucheron aquamarine clips, which perfectly complemented the aqua flowers in the fabric:

 

On 4 April 2013, the look was repeated when the Queen received an onorary Bafta at Buckigham Palace in recognition of a lifetime's support of British film and television - and for being the most memorable Bond girl yet'. Kenneth Branagh presented the award. The Boucheron clips were used again:

 

Below, the Queen is seen talking to guests at a reception at Buckingham Palace for the Queen Elizabeth Diamond Jubilee Trust, on the evening of 23 October 2013, after attending Prince George's christening. No brooch is visible:

 

The Queen selected this outfit again for a reception attended by 300 members of the Irish community held at Buckingham Palace on 25 March 2014, accessorising, of course, with her diamond and Emerald shamrock brooch:

Another chance to admire this outfit came thanks to the Duke of York, who shared this snap of his mother with his brother and sister-in-law taken at Buckingham Palace on 10 February 2015, just before the start of a joint 50th birthday celebration for the Earl and Countess of Wessex. Again, the Boucheron clips seem to be a fixture with this look:

 

 

Angela Kelly Turquoise Suit with Scalloped Hem

Another great Angela Kelly suit for the Queen: both the dress and the jacket are in turquoise silk and feature scalloped hems with multi-colour embroidery. The dress, moreover, has rainbow embroidery all over. The multi-coloured detail is picked up with the hat as well, which is a flat-crowned style trimmed with ombré curling feathers.
We first saw this outfit during the most recent Canadian tour, on 4 July 2010, when the Queen and the Duke of Edinburgh visited Woodbine Racetrack in Toronto for 151st Running of The Queen's Plate Stake. The City of London Lily brooch was worn:

 

On 11 May 2011 the Queen hosted a reception to recognise young people working in the British Performing Arts at Buckingham Palace, which she attended wearing the dress by itself, accessorised with one of Queen Victoria's Bow brooches. During the event, the Queen met, among others, actress Helen Mirren:

 

 

On 1 June 2011, the Queen wore the dress and jacket again for an investiture ceremony at Buckingham Palace, during which she appointed Sir Jerry Mateparae, then Governor-General Designate of New Zealand, as Additional Knight Grand Companion of the New Zealand Order of Merit. The Queen, predictably, wore the New Zealand Silver Fern brooch:

 

 

On 5 July 2011, the dress got another outing when the Queen wore it to an investiture ceremony at the Palace of Holyroodhouse in Edinburgh (below, the Queen with George Walker as he presented him with an OBE for charitable services):

 

 

We didn't see this worn again for quite a long time, until the Queen repeated the outfit on 28 October 2013 at a reception for Commonwealth nations representatives at Buckingham Palace. Below the Queen is seen speaking with Commonwealth Secretary General Kamalesh Sharma. This was also the first time we saw a relatively new addition to the Queen's brooch collection, a gold, diamond and blue pearl creation by Eyris Pearls, a personal gift from New Zealand Prime Minister John Key. The brooch was a truly fitting choice, as the shade of the pearl matched perfectly the blue of the dress:

 

 

On 29 May 2014, we again saw the suit, complete with a brooch in gold filigree, at another Buckingham Palace reception, this time for Leonard Chesire Disability, where the Queen met, among others, Professor Stephen Hawking. A brooch in gold filigree was chosen:

 

 

Only a few months later, 17 July 2014, the outfit was worn again to re-open the renovated railway station at Reading, Berkshire. The Eyris pearl brooch was worn again:

 

This was a perfect choice, as it allowed the Queen to truly stand out among all the high-visibility clothing in the group photos:

 

 

The dress alone was worn again on 21 July 2015, when the Queen received Jocelyn Roy-Vienneau, upon her appointment as Lieutenant-Governor of New Brunswick, Canada. One of Queen Victoria's bow brooches was used:

 

 

 

 

 

 

Powder Blue Suit and Flower Trimmed Hat

This, I think, is a fab look for the Queen. A skirt suit in powder blue silk crepe, with the jacket pockets decorated with silk bows, and a straw hat with a large silk sash and oversized silk bloom.

Interestingly, the first appearance of this look was dress only. Although I can't be 100% certain about it, I'm pretty confident the powder blue dress the Queen wore on 15 March 2006 for a reception at Hillsborough Castle in Belfast, Northern Ireland, for Action for Children, an organization of which the Queen is patron, is the one that matches this jacket and is usually worn underneath. The opaque fabric with shiny silk accent around the waist is reminiscent of the shiny details on the jacket and hat. The Boucheron aquamarine and diamond clips were worn:

Then it was time for another dress-only appearance several years later, on 14 October 2010, for an audience at Buckingham Palace with the Ambassador of Swaziland Mrs Dumsile Thandi Sukati (seen below) and others. The Boucheron aquamarine and diamond clips were worn:

On 17 October 2011, the Queen wore the suit, minus the hat, to the official opening of the Round Square International Conference at Wellington College, in Crowthorne, Berkshire. She paired it with one of Queen Victoria's diamond bow brooches:

However, the complete ensamble was first worn on 23 November 2011, when the Queen and the Duke of Edinburgh visited Admiralty House in London for the formal inauguration of the Duke as Lord High Admiral. The Queen accessorised her look with the Boucheron aquamarine and diamond clips and a naval badge:

Note the bow detail on the pockets:

Another appearance for what I strongly believe is the matching dress came on 21 May 2013, when the Queen wore it for an audience at Buckingham Palace with Croatian President Ivo Josipovic and his wife. The Boucheron aquamarine and diamond clips were worn again:

On 15 June 2013, after Trooping the Colour, the Queen changed into this suit to pay a visit to the Duke of Edinburgh (BBC video here), who was convalescing at the London Clinic after undergoing exploratory abdominal surgery earlier that month. The Boucheron clips were worn once again:

This look was repeated on 8 August 2013, when Her Majesty inspected the Royal Scots Borderers outside the gates of Balmoral Castle at the start of her annual stay in her Scottish residence. The badge of the Royal Regiment of Scotland was, predictably, pinned to the Queen's jacket:

On 19 March 2015, the dress made another solo appearance, for an investiture ceremony at Buckingham Palace, during which the Queen presented actress Kristin Scott Thomas with a damehood for services to drama. The Boucheron clips seem to be something of a fixture with this look, and were used again, although they can't be seen in the photo below (SkyNews video here):

On 13 November 2015, the Queen wore again the dress on its own for a meeting with Indian Prime Minister Narendra Modi at Buckingham Palace. She paired it with the Flame Lily brooch:

On 5 February 2016, the Queen repeated the dress to receive Sheikh Sabah Al-Ahmad Al-Jaber Al-Sabah of Kuwait at Sandringham House for a meeting and luncheon. Empress Marie Feodorovna's sapphire and pearl brooch was worn:

On 22 April 2016, the day after her 90th birthday, the Queen repeated the suit, with her trusty Boucheron clips and a silk scarf, to greet President and Mrs Obama upon their arrival at Windsor Castle for a private lunch (Daily Mail article here):

On 7 March 2017, the Queen repeated the dress for investitures at Buckingham Palace. She wore the Queen Mother's aquamarine Art Deco brooch: