The Queen turns fashionistas everywhere green with envy as she rocks neon birthday outfit

The Queen proved that style knows no age limits as she pulled out all the stops with an eye-catching lime green outfit on her official 90th birthday.

While other royals appeared in more neutral palettes, the monarch took centre stage in a vibrant green coat and dress by Stewart Parvin and matching hat by Rachel Trevor Morgan, decorated with cerise coloured flowers, at the Trooping the Colour celebrations.

Her choice of a lime hat and outfit went down an absolute treat on Twitter.

Her diamond Brigade of Guards brooch – appropriately chosen for the military spectacular – combined the badges of the five Household Regiments – the Grenadier, Coldstream, Scots, Irish and Welsh Guards.

The Duchess of Cambridge recycled the cream Alexander McQueen coat dress that she wore to her daughter Princess Charlotte's christening, but teamed it with a striking pale pink hat with large floral decoration by Philip Treacy.

Kate wore her hair in a low, side chignon, and opted for oversized pearl earrings.

Followers of the Duchess's fashion, WhatWouldKateDo.com described her outfit as "ravishing", adding: "Kate's gorgeous updo and Philip Treacy hat for Trooping the Colour are blowing our mind!".

Her large earrings did, however, according to some, appear "so big she looks like she's receiving radio transmissions".

The Duchess of Cornwall's look complemented Kate's pale ensemble as they rode in a carriage together with Prince Harry.

Camilla wore a neutral Anna Valentine dress and coat and a feathered hat by the same designer as Kate, Philip Treacy.

Another burst of colour came from Princess Beatrice, who followed in the footsteps of her luminously dressed grandmother by choosing bright headwear – an orange twist hat.