No designer was given for the dress, but it is believed to be from Catherine Walker. The basic style is almost identical to a Catherine Walker suit Diana wore the previous fall in Korea, and the aesthetic - a plain but bold color enhanced by a simple decorative trim in an equally bold color - is very characteristic of Walker when she wasn't constrained by the demands of Diana's public wardrobe requirements.

Diana was never seen publicly in this outfit again, which was unusual. Also a bit unusual is that while Diana liked to have shoes (and often a handbag) made to match the color of her outfits, in this instance they appear to be navy, matching each other but not the blue of the dress. Walker's partner revealed decades later that when Walker made up design samples they were always in Diana's size, in case the Princess needed something in a hurry, so it's possible this was an outfit Diana borrowed from the designer for this one occasion.