Practicing his signature brand of arty minimalism, Francisco Costa replaced the sharp angles and dark colors of his Fall collection with soft, organic shapes and light-reflecting neutrals. It made for a Spring collection more sensuous than sexy—and more youthful in feeling than his recent efforts. He opened with a white one-sleeve bubble dress that, like the needle-punched nylon coat that came down the runway a few looks later, caught air behind the model as she walked. When he wasn’t experimenting with volume, Costa was creating interesting textures: smocking and puckering cotton voile for an A-line shift, or hand-pleating and pintucking an organdy dress. Playing natural off techno, and sheer against opaque, the designer sent out mohair jacquard tank dresses that shaded from black to brown to gray and revealed subtle swaths of skin. The only departure from the show’s earthy palette was a group of crinkled silk-cotton tank dresses and asymmetrical shifts in shades of pale aqua, citron, coral, and jade.