Artist Richard Grosvenor, with his wife, Margot, was the honoree of the Summer Soiree.

Newport is known as a formal party town.

Men keep their tuxes pressed; women have an assortment of gowns set to go.

There’s at least one black-tie party per week during the summer. And the one bash that stretches Newport’s formal dress code to beyond the expected is the bash put on by supporters of the Newport Art Museum.

Their invitation calls for “creative black tie.” And on July 12, the sold-out crowd of more than 350 more than fit the bill.

Women wore gowns boasting of patterns, appliqués and multiple colors; several men put a tuxedo jacket over pin-striped shirts and topped off the outfit with a bow tie.

One male guest turned up in an old-fashioned silk smoking jacket; another wore a kaftan.

A quick glance around the grounds of the Newport Museum’s campus revealed swirls, stripes, pastels, florals and layers of chiffon. The flared skirt on Harriet Higgins’ green gown had six layers, including two layers of slips; one was of tulle and the others chiffon.

The chairwoman of the event, Diane Beaver, wore a slight-hint-of-green floor-length Vera Wang creation that matched the color scheme of the party. It was strapless, simple, and, like the rest of the outfits at the party, elegant. She paired it with a thick tripled-strand green choker.

“We want this party to be vibrant, and I wanted to match the motif,” she says. “Most of us will be seeing each other at other parties this summer, and we want this one to stand out as memorable and different.”

NAM’s A Summer Soiree was a salute to artist Richard Grosvenor. Grosvenor, whose works were on display in the gallery in a new show, “Richard Grosvenor: Newport Muse and Mentor” (through Oct. 13), is best known for seascapes.

“This is a real appreciation of a wonderful, man, artist and educator,” notes Diana Slocum, who co-chaired the event with Robert G. Manice, Mary Ellen Grosvenor (daughter-in-law of Richard Grosvenor) and Diana Bunting. “He has taught so many people so much.”

Guests dined under a tent decorated with white lanterns and chandeliers. The table centerpieces were pale pink roses in a vase, and they were placed on pale green tablecloths. Some of the table coverings had a coral pattern; others were thick stripes.

Though the theme of the party was green, “Blue is my favorite color,” said Grosvenor, who turned 80 this week, and greeted guests in a receiving line with his wife, Margot. He was pleased that the evening brought in $250,000 for the museum.

The fact that longtime supporter Jacalyn Egan and the museum’s acting director Elizabeth Goddard wore Grosvenor’s favorite color was “purely a coincidence,” they both say. They add that they are hoping the party will highlight the museum’s mission to educate and inspire diverse audiences.