NEW YORK (Reuters) - Designer Jason Wu, a favourite of first lady Michelle Obama, on Friday showed luxurious outerwear in his fashion show that played up elements of style he called "unflustered beauty."

Wu's fall 2014 collection used soft amethysts, powder grays and embroidered blacks. His fabrics and materials were, as always, luxurious.

"The inspiration was really something quite darkly romantic," he said after his show. "Unflustered beauty, I call it."

Wu enjoyed a huge publicity boost when the first lady wore his one-shouldered white gown during inaugural celebrations in 2009. A double-boost came at the inaugural festivities in 2013, when she wore a red chiffon gown designed by Wu.

Michelle Obama has become known for boosting the profile of younger American designers when she wears their clothes.

"The woman I design for ... is a modern woman," Wu said. "She loves clothes. She loves detail. She loves luxury and she loves texture."

His latest collection included looks he described as "cozy beautiful outerwear," a reference to his three-quarter length overcoats in angora, alpaca, cashmere and mink.

"It's the most luxurious outerwear you can possibly imagine," he said.

But he paired classical outwear with body-skimming gowns of velvet, silk and chiffon to evoke sexy elegance as well as cozy comfort.

Wide-leg trousers in wool, silk and crepe, and jackets trimmed in mink, raccoon and silver fox carried the theme of cozy luxury into his day wear.

Fashion Week in New York, a semi-annual series of shows, runs through next Thursday, with the latest looks presented by such well-known designers as Diane von Furstenberg, Carolina Herrera, Michael Kors, Calvin Klein and Ralph Lauren.