The slipdress is no small moment in Calvin Klein’s minimalist lore. Back in the Nineties, he catapulted it into the fashion stratosphere with various permutations, including the skimpy, sexy kind that Alicia Silverstone famously trotted out for her disapproving father in 1995’s “Clueless.” Francisco Costa’s spring collection for the house was predicated on a more ethereal version of the lingerie based on a body-skimming, below-the-knee cut. It was a positively gorgeous exercise in building a collection of distinctive pieces around a single concept.

Costa introduced his slipdress in a peachy nude that brought to mind household underpinnings of the Forties. Retro in color only, the dresses were done with layered bralette effects, darts, sheer insets and winding seams that provided subtle decoration while boosting the look’s demure sensuality. It was great to see Costa engage with something so delicate when he often fixates on structure, volume and architectural construction, here gracefully adapted to a gentler form. Sturdier tailoring was interspersed throughout with variations on the classic, satin-lapeled tuxedo jacket, usually worn with matching culottes. Still there was a cohesive softness to the clothes, which came in shades of pale yellow, hazy lilac and gunmetal that blended beautifully with the blush tones. By comparison, the interlude of black styles was slightly jarring. But in a season when designers have been patting themselves on the back for shunning black, it was almost a relief to see it again.