When you play a "swan" (the meaning of which will be explained later), you have to be an elegant animal on the red carpet: the show doubles as Ryan Murphy's latest film, Feud: Capote vs. The Swans, which premiered on FX on January 31. (It will stream on Hulu the next day.)

In the limited series, Moore plays socialite Anne Woodward in a shiny black and white Balmain dress with a swan design. The strapless dress had beaded accents and a bustier top with feather sequins, People reports. She wore platform heels, 18k white gold earrings, and a Cartier bracelet and ring, and was styled by Brad Goresky.

"When the swans go to the Black and White Ball," Goresky wrote on Instagram." @demimoore in @balmain gown and @cartier jewelry at the premiere of @feudfx, styled by me."

Moore played up the name of the show on the red carpet, and her youngest daughter, Tallulah Willis, noticed and wrote that her mother's look "really surprised me and left me speechless." The motif was inspired."

Moore and her co-stars, including Chloe Sevigny, Naomi Watts, Diane Lane, Calista Flockhart, Molly Ringwald, and Tom Hollander, wore coordinated black and white ensembles. (Moore, however, was the only one to boldly incorporate the swan theme. What is a "swan" in this context? As Page Six puts it, the "swan" is "the label that writer Truman Capote gave to a group of New York socialites. [Watts, who plays Babe Paley, tells "Entertainment Tonight" that "it's an extraordinary group of women [and great roles]," and Sevigny, who plays C.Z. Guest, says, "I mean, love and betrayal, the main themes, we've all been through that." How heartbreaking it is when someone you trusted turns their back on you, whether it's a friend or a lover: ...... I think there's something we can all relate to," she said.

This is the second installment in Murphy's "Feud" franchise, following 2017's "Feud": with Susan Sarandon as Bette Davis and Jessica Lange as Joan Crawford.