Ellsworth Kelly had the best seat in the house at today's Calvin Klein Collection show. Francisco Costa recently partnered with the 90-year-old artist; their striped shift dress, based on Kelly's 1952 canvas Red Yellow Blue White, was hanging in the windows of the Madison Avenue flagship earlier this Spring, and will soon be donated to the Costume Institute.

Today's Resort show was a continuation of that collaboration—after a fashion. Costa said the bold palette—unusual for the designer, who usually prefers neutrals—was inspired not by Kelly's paintings but by the colors he saw in his studio. An ultramarine ultrasuede apron dress was the vibrant standout, but there was also a fern-green ultrasuede coat and zip-front dress, and a rich chestnut-brown nubuck work jacket and pencil skirt.

Costa claimed Irving Penn's Small Trades book as another point of reference. In the end, though, the strongest message was the collection's seventies mood. Credit goes to all that ultrasuede. "There was a sense of lightness [to the seventies], a great spirit," he said, "but obviously we don't do it literally." True. Even in that body-beautiful era, we doubt women had the abs of steel required for Resort's spate of midriff-exposing tops. Amid all the cropped sweaters and sweatshirts we've been seeing, Costa's harness top looked fresh. The most persuasive piece was more discreet: a black washed-silk charmeuse tank dress with just a flash of bare skin exposed in the back.