The “wild chic” dress code on view at stage director Robert Wilson’s fund-raiser Saturday night at his Watermill Center in Water Mill, N.Y., reflected the aesthetic that the East End’s fashion leaders — the women hosting hot-ticket parties — are setting this summer: anything goes.

The long-standing beach-resort look, with its candy-colored designs popular in Palm Beach, Fla. and St. Barts, is mingling with urban high fashion. Lilly Pulitzer’s whimsical prints are still popular, but so are a range of other fashions, from silky Gucci gowns and diamonds, to designer jeans and Indian beads.

The varied looks can be seen not just on hostesses’ backs, but also in the shops situated in East End communities’ retail districts. Sometimes the connection is quite literal: Rory Tahari, the wife of fashion designer Elie Tahari, wore a beaded and embroidered smoky white Tahari evening gown when she threw a recent party at her home to celebrate her husband’s new East Hampton boutique.

“How does one dress in the Hamptons? It’s so varied. It’s unique. It feels very free,” one half of the design team Viktor & Rolf, Vicktor Horsting, said, during an interview at the Watermill Center benefit. At that party, three very social galagoers sported three very different looks that epitomize the range of attire favored by various Hamptons hostesses: Beth Rudin deWoody in a vintage kaftan, Brooke Neidich in a knee-length light gray cocktail dress by Alber Elbaz Lanvin, and Jessica Joffe in a floor-length khaki and taupe evening gown by Vicktor & Rolf.

Some of this summer’s fashion chaos is simply generational. When restaurateur Jerry Della Femina and his reporter wife, Judy Licht, opened their Drew Lane home Saturday in East Hampton for a party celebrating the release of the film “Becoming Jane,” Ms. Licht wore white pants and a form-fitting periwinkle top. Meanwhile, her daughter, Jessie Della Femina, wore a Mara Hoffman hot-pink minidress that seemed suitable for either the beach or the ballroom.

Over at her Further Lane estate in East Hampton, Jessica Seinfeld took a different tack when it came to dressing for a party Saturday that raised money for her children’s charity, Baby Buggy. She wore a prim, belted Ferragamo dress, which didn’t exactly look like the “beach casual” attire specified on the invitation.

A Southampton summer resident, Jamee Gregory, likes trousers but said she tends to dress up her look when she throws parties at her home, where she insists guests tour her gardens. On Friday, for a party “just celebrating summer,” she wore a lace Wolford top, sequined pants, and kitten heels. “I was comfortable but I felt glamorous too,” she said.

But not all hostesses dress up for their own parties. “When I go out I usually wear dressier than when I entertain at home,” a philanthropist, Emilia Saint-Amand, said. “Home is pants, out is a dress or skirt. I like orange and pink. I’m a Lilly girl, so everything coordinates.”

Not everyone likes the “anything goes” trend. “Some people think they’re in Park Avenue with the roof down,” a contributing editor at Vogue, William Norwich, said, noting that he favors a more traditional look for Hamptons hostesses. “Some women do a wonderful job of it. It’s about prints and fabulous jewelry. It’s been the same look since Pucci and jet planes.”

But the great divide among Hamptons hostesses may not be whether they wear capris or a ball gown, but whether they wear heels or flip-flops.

Hostess Marcia Mishaan said she always wears high heels, often paired with jeans, when she hosts at the Sagaponack home she shares with her interior decorator husband, Richard Mishaan.

By contrast, an art collector and philanthropist active with the Whitney Museum of American Art and the Central Park Conservancy, Suzanne Cochran, said she’s a flip-flop devotee. “I don’t like wearing heels,” she said. “You can’t imagine how hard it is to stand there when your heels are sinking into the grass.”

Ms. Cochran added, “There are two kinds of hostesses: the sexy and cute, and the practical — I’m the practical.”

1) Rory Tahari, in Tahari, posed poolside at the party she and her husband hosted July 14 for the new Tahari boutique in East Hampton.

2) Katherine Ross, in Pucci, with Beth Rudin DeWoody, left, and Jane Rosenthal, at a luncheon she hosted last week.

3) Jodie Eastman wore a tunic she bought this spring in St. Bart’s for the party she and her husband, John, threw July 20 for the New York Stem Cell Research Foundation.

4) Jessie Della Femina in Mara Hoffman at home Saturday for a bash celebrating the release of ‘Becoming Jane.’