The Queen surprised the crowds on her arrival at the annual Trooping the Colour ceremony by wearing a show-stopping bold green outfit. Her Majesty's vibrant green coat and dress, by Stewart Parvin, and hat by Rachel Trevor, made her instantly recognisable to the huge crowd of well-wishers who had gathered to celebrate her birthday.
The Queen, who is attending her 65th Trooping the Colour, accessorised her look with a matching green umbrella and pink flowers in her hat, along with a Brigade of Guards brooch.
The Queen wore a bold green outfit
According to the monarch's daughter-in-law, Sophie, Countess of Wessex, the Queen chooses bold colours intentionally so her subjects can spot her from far away. Speaking about her for The Queen at 90 documentary, she said: "She needs to stand out for people to be able to say 'I saw the queen.'
"Don't forget that when she turns up somewhere, the crowds are two, three, four, 10, 15 deep, and someone wants to be able to say they saw a bit of the queen's hat as she went past."
The Queen's biographer Robert Hardman has also spoken about the Queen's bright outfits, telling BBC Radio 4's Today: "She is engagingly modest. My favourite remark she ever said was 'I can never wear beige because nobody will know who I am'."
The Queen wears bright colours so the crowd can spot her easily
The Queen was joined in the Queen's Carriage by husband Prince Phillip as they travelled from their Buckingham Palace home for her official 90th birthday celebrations.
The couple followed after The Duchess of Cornwall, the Duchess of Cambridge and Prince Harry, who rode in the Barouche carriage, as well as Prince Andrew with Princess Beatrice and Princess Eugenie along with the Earl and Countess of Wessex with their two children, Lady Louise Windsor and James, Viscount Severn.