green day; The private-jet set are not just cutting carbs, they're cutting their carbon footprints, says William Norwich.

Byline: William Norwich

From brunch to biodegradable bridal bouquet, dinner to disco, society's favorite color is green these days-save-the-planet green, I mean, not just the dye of money or those amusing numbers in Prada's fall collection.

How green is my calendar! As I write, producer Jane Rosenthal is finessing "a green initiative" for the Tribeca Film Festival's opening-night party, and the young philanthropist Claire Bernard is inviting friends like Lauren Davis to sit at her table at the American Museum of Natural History's April 25 luncheon and lecture titled "Living Green in the Face of Global Climate Change"-certainly, as Claire says, a different aspect to the museum than just its Winter Dance.

Event designer Bronson Van Wyck's summer projects will be, if not a deep shade of green, a definite celery color-recyclable plants and trees and environmentally friendly LED lighting "that uses a tiny fraction of the power of traditional theatrical fixtures, resulting in less cabling and less electricity." And where people once solved their entertaining quandaries by asking, What would Nigella do? they now turn to Danny Seo, an eco-stylist born on Earth Day 1977, whose Web site, CBS's Early Show appearances, and books-especially his Simply Green Parties-have garnered him guru status. (Last May, he gave the commencement speech to the graduating class of UC Berkeley.)

Even that Old Guard symbol of springtime, the Kips Bay 2007 Decorator Show House, is going green. First, there is the $25 million Beaux Arts house itself, 14 East Eighty-second Street, a renovation project by celebrated green real estate developer Janna Bullock; second, all the rooms will be painted (unless some decorator cheats) with show-house sponsor Benjamin Moore's newest product, Aura, an acrylic the company says exceeds the country's most stringent air-quality regulations.

"I am not sure the world will be saved by paint that is environmentally safe, but it is a wonderful concept," the architect Stephen Miller Siegel, who is designing a sitting room for Kips Bay, noted after one of the show house's preview events.

Having attended a party at Ghislaine Maxwell's house for Allegra Hicks, celebrating Hicks's new boutique at 1007 Madison Avenue, one of my colleagues says that the eco-lifestyle was a major topic of conversation, whether it was extolling the virtues of OZOcar-Manhattan's premiere, if only, radio fleet of chauffeured Toyota Priuses (I tried an OZO last week, and since it uses less fuel it is not only eco-fab but also more affordable than most car services in the Big Apple)-to who might trade their Park Avenue flat for a condo in architect David Rockwell's new 31-story Riverhouse, perhaps the greenest apartment building in town. Friends were asking Renee Rockefeller about her prospective line of organic children's clothes, and they were talking about the new eco-manners-say, what to do at your next dinner party if someone lights up: Pot smoking, greener than drink, is always organic, isn't it?