Diane Lane is a sensation in scarlet as she heads to Good Morning America, where she remembers late Feud co-star Treat Williams

Diane Lane was a sensation in scarlet as she was spotted attending a taping of Good Morning America in New York on Thursday.

She has thrown herself into the publicity whirlwind for her upcoming FX show Feud: Capote vs. The Swansthe latest delicacy from Ryan Murphy.

The 'Swans' were the New York socialites who welcomed Truman Capote into their circle, but ruthlessly threw him overboard when he aired their dirty laundry in public.

As she showed up in Manhattan on Thursday to make the media rounds, Diane looked elegant in a silk-lined red pantsuit that flattered her slim frame.

While it appears on Good morning AmericaDiane, 59, fondly remembered her late co-star Treat Williams, who appeared on Feud as CBS President Bill Paley.

Treat was killed last summer at the age of 71 in a horrific traffic accident in which he was struck by an SUV while riding his motorcycle.

During her final interview, Diane praised Treat, calling him “such a joyful man, and his joy will stay with us forever.”

She recalled being “intimidated” by him when she glimpsed him at a party in New York in 1979, just after he impressed in the films 1941 and Hair.

Diane herself was only 14 years old at the time and had just made her film debut in the comedy A Little Romance, starring Laurence Olivier.

Describing the party on Good Morning America, she said that “Liza Minnelli was dating Baryshnikov at the time and Lucille Ball was there.”

Diane was trying to “get close to Lucille Ball” when Treat, a dashing new movie star in her late twenties, sauntered into the party.

“And I had auditioned for Miloš Forman to try to be a 12-year-old hippie who might be in the cast of Hair,” she recalled.

“But he was the It Guy, he just had… I mean, he had chest hair and he had long hair, and he brought it from Hair still. Everyone was like, “Look at this guy, he has a career.” He walked into the room.”

Decades later, when Diane and Treat crossed paths again for Feud, she told the story to him and “he remembered it too,” joking, “I know, and now look at me!”

At another point on Thursday, Diane could be seen stepping out in a racy black collared dress and a matching pair of heels.

Feud: Capote vs. The Swans premieres on January 31 with Tom Hollander as Truman Capote, in the story of his dramatic exile from New York's socialite.

Truman worked his way into the highest echelons of New York society and became the confidante of many of its top women, whom he called his “Swans.”

The breakthrough came in 1975, when he published a now infamous short story in Esquire called La Côte Basque, 1965, in which he pranked his extremely thinly veiled friends.

Enraged and wounded by his betrayal, the Swans closed ranks and drove him from their circle, much to Truman's shock and dismay.

“What did they expect?” he groaned. 'I'm a writer and I use everything. Did all those people think I was just there to entertain them?'

Diane plays the acerbic society expert Nancy 'Slim' Keith, who, as the husband of Howard Hawks, hopped to an English baron via Leland Heyward.

In La Côte Basque, 1965, Slim is depicted as 'Lady Ina Coolbirth', an American who has assimilated into the British aristocracy and spends the story happily spreading the dirtiest secrets of her dearest friends.

Meanwhile, Naomi Watts stars as Babe Paley, the wife of CBS President Bill Paley and a woman widely considered one of the most beautiful and stylish in New York.

Of all the Swans, Babe was among those most hurt by the Esquire piece, as she had considered Truman a close and trusted friend.

To add to her misery, the story was published at a time when Babe was battling what turned out to be a terminal bout of lung cancer.

La Côte Basque, 1965 contains an anecdote in which a stand-in for Babe's husband has an adulterous one-night stand with a stand-in for Maria Harriman, wife of the diplomat-turned-governor of New York, Averell Harriman.

In the Esquire piece, the governor's wife gets her period on the magnate's sheets, forcing him to spend the night trying to remove the stains before his wife comes home.

Chloe Sevigny, meanwhile, plays horsewoman and model CZ Guest, who remained friends with Truman after the furor over the Esquire story — an act of loyalty that may have been made easier by the fact that she wasn't turned into one of his characters.

Calista Flockhart plays Jackie Kennedy's perpetually overshadowed younger sister Lee Radziwill, with Molly Ringwald as Johnny Carson's second ex-wife Joanne, whose Los Angeles home became the site of Truman's death.

Demi Moore plays Ann Woodward, a social climber who became a scandalous figure when she murdered her wealthy husband at home with a shotgun and avoided a trial by insisting she thought he was a burglar.

When she learned that Truman's story was about to re-expose her past and imply that she had deliberately killed her husband, Ann committed suicide.

“Well, that's that,” her mother-in-law remarked. “She shot my son, and Truman just killed her, and now I don't think we have to worry about that anymore.”