Don't expect to see day clothes on Jenny Packham's runway anytime soon. "Other people do day better," she said backstage before her Fall show, going through racks of beaded gowns in washed pastels and muted jewel tones. "We've found that the more niche you are, the better off you are."

Packham's philosophy is welcome, as it resulted in a tight collection of gorgeous formalwear that was broad-reaching but not boring. Inspired by seventeenth-century Paris salons—"where strong-minded women met to discuss arts and culture"—the designer put out a line of relaxed gowns and a few separates. A red tea-length dress, beaded in the style of Dorothy's ruby slippers, was made sexy by significant sheer paneling down the front. A dusty peach organza crop top, covered in red and white floral-patterned beading, paired nicely with cherry-colored high-waist trousers.

And then there were the coats. "Everyone always seems so cold on the red carpet," Packham said, referring to her extensive celebrity client list (which includes Emily Mortimer, Angelina Jolie, and of course, Kate Middleton). The solution—beaded wool dress coats in peach, gray, and black—should belong in every opera-going girl's wardrobe.

Packham may not be cashing in on button-ups and miniskirts, but her business is nonetheless growing. For Fall, the accessories collection, launched just a few seasons back, featured earrings with geometric-cut sky blue and opal stones laid in rose gold, and a fancy white clutch adorned with wing-shaped Swarovski brooches. "It ties in well with the clothes," Packham said. She's right.