The Duchess of Cambridge steps out in Stella McCartney Stella McCartney was Kate's designer of choice for a visit to London's National Portrait Gallery today. The Duchess of Cambridge played a diplomatic blinder this morning, arriving for the opening of the 'Road to 2012: Aiming High' exhibition at the National Portrait Gallery in London wearing a dress by Stella McCartney - the designer behind the Team GB Olympic kit. The Duchess has only been spotted in Stella once before - a salmon pink satin pussy bow dress she wore for dinner at the Waterside Inn in Bray, Berkshire last summer - a fact which is hard to believe given the designer's gift for designing elegant classics for the modern woman. The bright blue tunic dress from the Stella McCartney autumn 2012 collection is currently available to buy on the Matches, MyTheresa and Selfridges websites for £510-£515, but will no doubt be flying off the virtual rails as I type. As a side note, it's also nice to see Kate take a break from her beloved nude courts and team the dress with some more modern black kitten heels, but for us, the necklace was a flourish too far. Some things are best kept simple - a motto Stella has built her fashion empire on.