There was enough paillettes and shimmer to outfit a Bob Mackie extravaganza at the American Museum of Natural History's Museum Dance Thursday night.

"Was the dress code 'sequins'?" asked a confused guest, surveying a room full of glittery micromini frocks.

In fact, the evening's theme was "Green," inspired by the institution's current exhibit "Climate Change." And so the fete, sponsored by Dior Beauty and Judith Ripka, touted organic and sustainable food for dinner (translation: vegetables and fish) and "energy efficient production" (aka dim lighting). Between sips of Champagne and vodka cocktails, partygoers were happy to share their favorite environmentally conscious tips.

"I ride my bike. I take the subway," offered Leigh Lezark.

"I think vintage [clothing] is a great way to go green," enthused Jessica Alba.

"I even recycle the plastic wrappings from the food I buy," said Claire Bernard.

"Anything to make a better place for my baby," espoused Milla Jovovich. After cocktails in the Cullman Hall of the Universe, guests including Fabiola Beracasa, Julia Restoin-Roitfeld, Tinsley and Topper Mortimer, Tara Subkoff, models Behati Prinsloo and Anne Vyalitsyna, Elise Overland, Lauren Santo Domingo and Alex Kramer made their way to dinner, where Maggie Betts celebrated her birthday with hats and cake.

Dancing and dessert followed and most stuck around until past midnight, crowding an overwhelmed bartender who had even Cash Warren and Alba waiting for drinks.