Duchess of Cambridge arrives at Fortnum and Mason wearing a Missoni coat.

The Queen, the Duchess of Cambridge and the Duchess of Cornwall seemed to have colour-coordinated their outfits today for a visit to London's boutique department store, Fortnum & Mason.The royals were all dressed in shades of blue when they arrived at the famous Piccadilly store to meet military personnel and tour the restaurant which has been renamed 'The Diamond Jubilee Tea Station' to mark the Queen's 60 years on the throne.

The Queen wore a pale blue outfit with a matching hat; Camilla was dressed in a navy blue coat with eye-catching white horizontal stripes at the top, while Kate, the newest addition to the Royal Family, wore a blue wool above-the-knee coat.

So far, so safe. But in fact, Kate's outfit broke from tradition in one subtle way. The Duchess, who almost exclusively wears British-based labels chose a coat by M Missoni, the second line of Italian fashion house Missoni. The powder blue coat bore all the hallmarks of the luxury brand famous for its elaborate knitwear, and palace sources have confirmed its origins.

But fear not British Fashion Council - ever the diplomat, Kate topped off her outfit with shoes by British designer Rupert Sanderson. To be fair, if one is going to stand around all day with one's step mother-in-law, grandmother-in-law and Boris Johnson chatting to military personnel, one should at least be able to indulge in a bit of luxury Italian fashion for the occasion.

The Queen, The Duchess of Cornwall and The Duchess of Cambridge arrive at Fortnum & Mason. PHOTO:AP