Inside the homes of Hollywood legends Bette Davis and Joan Crawford with FX's new show 'Feud'

"Joan was very good friends with a well-known decorator of the time, William Haines, who started out as an actor and then became a pretty famous interior designer," Becker said.

Becker said that William Haines "designed all the furniture that's in the living room, the kind of tufted furniture. We made those for the show, but they're based on his designs, which cost a fortune now if you can find them."

"Joan had all that furniture in her real house, and she also had plastic slipcovers on everything," Becker said. "For real. I mean, there's a lot of documentation of it, and my favorite photo is the one of her lying in bed with a plastic slipcover over the bedspread as she lies there. And that photo really exists. We didn't make it up. So it's pretty funny."

"She always had a portrait of herself over the mantel, so we had one made of Jessica Lange as Joan Crawford," Becker added.

"The color palette, a lot of the blue and the white is pretty close to what she had towards the end of the time she lived in this house," Becker said.

"I have a huge collection of vintage paint chips and paint charts and paint decks, and I use that to inform the color decisions I make," explained the production designer. "So that's a kind of research that I do that I find really helpful. And those colors are kind of different from modern colors, and my painters reproduce them."

"[Joan Crawford] was really a Hollywood celebrity, and her house is very glamorous," Becker said. "So that was important to [executive producer Ryan Murphy] and important for the feeling of the show, versus Bette, who lived in a much more kind of East Coast way ... So we stressed both of those differences when we were designing their houses and their looks."

Becker continued, "Bette Davis was from a town outside of Boston, and she went to boarding school on the East Coast. She really was like a Yankee."

"Bette had, for example, in her living room, a braided rug, like a colonial braided rug, and she had this kind of dowdy furniture with these little prints on it," Becker said. "Browns and greens, and it wasn't so glamorous."