Models walk in the finale of the Michael Kors Spring 2013 collection during Fashion Week in New York, Wednesday, Sept 12, 2012.[Photo/Agencies]

Katie Holmes greeted well-wishers in a black leather blazer and gold beaded heels as she became the latest celebrity to take a serious stab at fashion with her Holmes & Yang preview at New York Fashion Week on Wednesday.

The celebrities who once lined the front rows of these seasonal previews in party dresses have increasingly made their way backstage into positions of power.

Celebrity names are commonplace on mass-market brands: The Kardashian sisters, Venus Williams, Jennifer Lopez, Jessica Simpson, Avril Lavigne, Daisy Fuentes, Heidi Klum and reality stars Whitney Port and Lauren Conrad each have department-store brands.

But a handful have also become serious fashion forces. Mary-Kate and Ashley Olsen are among the most imitated - or sincerely flattered - US designers for their brand The Row, and this year were named top womenswear designers by the Council of Fashion Designers of America. Victoria Beckham's previews are among the week's most hotly anticipated, and paparazzi-free.

Gwen Stefani, Nicole Richie and celebrity stylist Rachel Zoe have also pulled away from the pack.

"The lines that are successful are very authentic," said Susan Kaufman, editor in chief of People StyleWatch. "The key is the celebrity being involved, being involved in the look and the concept, and to be proud to wear the clothes."

On that measure, Holmes seems ready to join the club. Showing at Mercedes-Benz Fashion Week seems a major commitment to the brand. "It was very clean but with a cool factor," Kaufman said. "I can easily see her (Holmes) wearing it."

MICHAEL KORS

Michael Kors' sunny disposition found a home in Southern California for the upcoming spring fashion season. He turned out an optimistic, cheerful and modernist collection that he said was inspired by the architecture, attitude and mostly the weather he enjoys every time he makes a trip to the West Coast.

"You could be sitting at the Beverly Hills Hotel, by the pool, and you could find this entire palette whether it's the palm green, the turquoise of the pool, the yellow of the sky - of the sun," he said in a backstage interview. "And I love all the architecture that we see whenever I go out to California. ... You're seeing a lot of that kind of geometry play into the collection here."

Stripes were strong, and he opened the show with a female model in a red-and-navy striped bodysuit with a zip-front navy skirt with a crisp white belt, while her male runway companion had on a green-and-navy striped pullover and striped pants. On later outfits Kors played with the proportion of the stripes, mixing thick and thin, and even horizontal and vertical.

Kors said he purposely included bright colors and fun details on clothes that, while technically for spring, get shipped in February.

OSCAR DE LA RENTA

Latex and leather: That's what keeps Oscar de la Renta modern while maintaining his position as the godfather of uptown style.

On his runway Tuesday evening, de la Renta equally paid homage to the decorative and frothy styles that have been his hallmark for more than four decades as well as the new technologies that keep fashion ahead of the pop culture curve.

One of the most remarkable looks was a two-piece dress made of ivory silk faille and with a feminine peplum around the hips that also featured a top layer of a latex flower appliques that could have been the icing on the most delicious cake.

Leather has been a staple of this round of previews for editors, stylists and retailers, but de la Renta took the risk with latex, which actually seemed even lighter and more supple than the buttery leathers the crowd has seen.

OSCAR DE LA RENTA CHILDRENSWEAR

Like a proud grandfather, de la Renta beamed Wednesday as bite-size models showed off his first full children's collection for spring, a garden party of floral and lace party dresses for girls and classic layered looks for boys.

One lucky little model hitched a ride in a wagon painted in a blue petal design to complement her red dress in the same print. Two boys toted skateboards for their strut down the runway and two others glided on scooters.

Some had their end-of-runway pause before the cameras down like the bigger pros - and all wore huge smiles.

De la Renta launched a small collection of kidswear for spring of this year. Generally, de la Renta children's party dresses last season didn't exceed $350 - far from the priciest in the lucrative toddler-with-bucks market.

BETSEY JOHNSON

Betsey Johnson threw herself a big, crazy 70th birthday party with pal Cyndi Lauper belting "Girls Just Wanna Have Fun" and confetti-slinging models prancing decade-by-decade down a runway in her wild clothes, including one clutching a not-happy-looking baby pig.

Johnson's grown daughter Lulu popped out of a huge faux birthday cake on stage and watched with her two young kids as grandma performed her signature cartwheel and splits.

If anybody deserves a night out, it's the flamboyant Johnson, a breast cancer survivor who lost control of her signature boutiques after Betsey Johnson LLC filed for Chapter 11 bankruptcy protection in April.

The brand will continue on a wholesale basis and online, with moderately priced clothing sold in department stores, along with accessories and other licenses.

So why not celebrate? Huge video displays offered glimpses of her rock roots in the swinging '60s, as models held up glitter-lettered signs marking the decades, culminating in new clothes for spring with a princess theme.

Johnson's actual birthday is Aug 10, 1942, but who's counting.

HOLMES & YANG

Holmes might have just tipped off the paparazzi on how to find her: They should look for a woman a camel-colored suede capelet with red shorts, or, if it's later in the day, maybe a strapless jumpsuit with beaded fringe running down the side.

Holmes and her design partner and longtime stylist, Jeanne Yang, didn't have a runway, just 14 models on pedestals.

One wore a black leather lingerie-style camisole with an olive silk button-front maxi skirt, and another had on a black lace slouchy blazer with black lace short - an outfit right on trend with what tastemakers have been seeing this round of previews.

Many of the outfits hit on the menswear silhouettes and luxury fabrics Holmes favors.

NANETTE LEPORE

It's not uncommon for little gifts to be given out at Fashion Week shows, but the one that awaited guests at Nanette Lepore was not the usual fragrance or hair-care item: It was a big blue Obama-Biden button.

Backstage, Lepore said she'd been upset that nobody seemed to be talking about the election. "So I decided, even if you don't support who I'm supporting, at least pay attention to it!"

Lepore delivered a colorful and snappy Spring 2013 collection, dominated by a brilliant shade of green she calls clover. "Greens were just feeling so fresh to me this season," she said.

The clover shade appeared in everything from jackets to tops to trousers to dresses to swimsuits, in solids and in prints. It was often accompanied by black and white, either in stripes or in checks.

RACHEL ZOE

Rachel Zoe showed that the relaxed glam she is known for doesn't always have to mean a bohemian maxi dress. She presented a collection that was a bit more of a tailored take on "effortless cool".

The first look out was a white skirt suit. OK, it was a maxi, to-the-floor hemline, but it was the sharp styling that will linger with the audience.

Even the tunic and fluid pants, jumpsuit and romper that seem to fit with Zoe's core muse had more strength to them, thanks to graphic, mod, black-and-white contrasts.

The paillete-covered T-shirts and sweatshirts also added a new twist.

She said she had in mind 1960s fashion icons Brigitte Bardot, Jane Birkin and Charlotte Rampling. They are, she said, "glamorous all the time and that's who I design for."

BIBHU MOHAPATRA

Bibhu Mohapatra was working on costumes for an opera in upstate New York not long ago when he saw an insect that fascinated him: a luna moth.

That graceful insect inspired his Spring 2013 collection, in which he embellished both daywear and evening gowns alike with intricate cutouts, filigree-inspired prints, appliques and embroidery.

For daytime, a sleeveless white top had "drapes", an almost winglike effect. It was paired with a steel-colored pencil skirt. An onyx leather dress was enhanced by intricate laser cutouts. A sea green and sand-colored suede dress with silk inserts was one of the most wearable daytime looks.

Some of the embellished gowns seemed a bit too busy. But a chartreuse and sand organza gown with a hand-pleated skirt made a wonderfully striking impression: the effect was that of a swirling breeze enveloping the model as she glided down the runway.

VIVIENNE TAM

Vivienne Tam took on the Five Elements of Chinese cosmology in an East-meets-West spring collection of three-color geometric applique and hexagonal cut work that moved with her models.

Touches of black patent shined like metallic silver and gold printed on cotton denim for tops and wide-leg cropped pants. A trench was also done in the bright silver.

A geometric design of white, jade green and black stole the show, in loose cropped pants, a short organza column dress and another looser and waisted dress with black straps and matching cutouts at the chest.

The yang? Reverse pleats at the hip in a long column dress. Nobody but the very thin, and hipless, can wear those.

NARCISO RODRIGUEZ

From the triangular cleavage cutouts to the plunging V-necklines, Narciso Rodriguez made his point with pointed shapes.

"It's a very graphic collection. It's kind of a signature at this point after so many years: the splicing, the color, especially black and white," said Rodriguez before his show on Tuesday.

But while the designer known for modern and architectural silhouettes showed a handful of black and white looks, color dominated the minimalist collection with blood-orange sheath dresses, a loose-fitting fuchsia blazer and silky tops with intricate, emerald embroidery.

The easy-breezy collection ended with a stream of silky soft, paper thin, slip dresses colorblocked with geometric shades of pink.

JENNY PACKHAM

British restraint? Not here.

The Jenny Packham catwalk was a parade of one glitzy, glamorous look after another, and she wasn't one to shy away from a single - or thousands of - beads, sequins and sparkles.

Packham wouldn't be doing justice to 1960s Las Vegas without them, right?

London-based Packham said in her notes that she took a long look at Lauren Bacall, Shirley MacLaine and Angie Dickinson, aka "The Rat Pack Mascots", as inspiration. If these muses were to swing open the closet doors in spring 2013, they would find Packham's checkerboard-beaded gown, a swinging trapeze-beaded mini and the ultimate hostess dress, an orange T-shirt gown with embellished long-sleeve cuffs.

MARC BY MARC JACOBS

Marc Jacobs threw a hipster picnic with a mashup of neon checks, plaids and stripes - large, small, wide, narrow - loaded into outfits as many as five at a time for his more moderately priced Marc by Marc Jacobs line.

Other looks for men and women were less busy. There was an edgy chic to a roomy ladies' button coat in off-white with embroidered silver dots, and another in solid bright pink with large pockets, vents and heather gray sleeves with matching pink trim at the cuffs.

Another button coat was more fitted, in a fuchsia pattern of smaller dots against dark blue.

But the line's spring show shouted bold, fun prints in bright orange, pink, purple and red.

J. CREW

J. Crew is sending its customer packing. The retailer presented a collection of upcoming styles on Tuesday that picked up influences from vacation spots around the world.

It was only natural to tap into the retailer's growing international presence, explained Tom Mora, women's vice president of design, in a pre-show interview. "I always have her (the J. Crew customer) in my head, and she travels with me. I'm mostly taking her to warm places."

One print on a pajama-top dress featured the image of a hotel and its pool - probably Miami in the 1950s. And there was pink, lots of it.

WHITNEY EVE

Whitney Port turned to the crown jewels of London in prints that evoked precious stones, crystals and rock formations in gray, greens and a broad range of blues, from sky to, well, jewel.

Solid white blazers and loose shorts offset the show of color in dresses and lightweight cigarette pants for the spring collection of her Whitney Eve line. She used light black and gray that way as well, including her finale look, a long dress of shimmying fringe panels.

The actress who rose to prominence on MTV's reality show "The Hills", earning her own spinoff, "The City", launched the Whitney Port label in 2008, making use of masculine tailoring with a feminine aesthetic.