People: Apr. 1, 1985

When the Princess of Wales appeared at a ball for Britain's Fashion Week, an almost audible gasp of surprise rippled through the assemblage of London designers. In other surroundings Diana might have prompted yawns: she had chosen a dressing gown--bathrobe to most Yanks--made from turquoise, fuchsia and cobalt-blue silk faconne and worn over a formal dress. "Wearing it in public put the royal seal of approval on it," said delighted David Sassoon, who designed the robe for her after seeing the boudoir look in U.S. publications. Meanwhile, Charles and Diana accepted an invitation to visit Ronald and Nancy Reagan this fall. Even now, Washington socialites are probably ordering their own new bathrobes.