When the cast and crew of “The Assassination of Gianni Versace: American Crime Story” attempted to recreate the life and fashion sensibility of the murdered Italian designer, immersing themselves in his flamboyant aesthetic was key to telling the story well.

So they set out to showcase his dramatic world with both setting and costume: Producer Ryan Murphy obtained permission to film the series, which debuts Wednesday on FX, inside Versace’s former home, Casa Casuarina in Miami, where the rooms are decorated with bold tile, frescoes and seashells. And actor Edgar Ramirez, who plays the doomed designer, embraced Versace’s creative vantage point, which was heavily influenced by classical motifs.

“He had a poster of the Roman empire in his shop in Calabria, [Italy,]” Ramirez said at a recent panel discussion of the series. “When we think about the Roman Empire, we tend to think about washed-out statues . . . But the reality is that the Roman Empire was very colorful. The blues were very intense and the gold was intense.”

Recreating Versace’s outlandish designs for the series became a painstaking project for Emmy-winning costume designer Lou Eyrich, who not only tracked down genuine vintage pieces, but created looks for the show without any cooperation from Gianni’s sister (and current artistic director of the brand), Donatella Versace, or the Versace company itself — which has denounced the entire production as a “work of fiction.”

“Gianni Versace was fearless and bold in his use of color. He understood the female physique and how to make a woman feel and look sexy,” says Eyrich, who has also designed the costumes for “American Horror Story.”

Versace was also fond of using mixed media in his designs. For example, a Greek key pattern seen on the border of the iron gates to his villa appears in his clothing for men. “The more you look [at his creations], the more you see [those motifs],” says Eyrich.

Since his death at age 50 in 1997, many of Versace’s pieces have been scooped up and preserved by collectors. Eyrich had to scour the Internet to outfit not only Ramirez, but Penélope Cruz, who plays Donatella, and Ricky Martin, who plays Antonio D’Amico, Versace’s domestic partner of 15 years.

Many pricey items were out of reach for Eyrich and her team: At stores such as the Way We Wore in LA, the asking price for a Versace shirt from the era is a hefty $1,500, and an animal-and-baroque-print skirt suit goes for $4,500.

“We didn’t have the budget to get the pieces we really wanted. We ordered a lot online,” Eyrich says. “We were competing with a lot of serious collectors.”

Of all the actors in the show, Ramirez was the one Eyrich was able to provide with the most authentic duds. “Almost all of Edgar’s costumes were Versace,” she says. “We sourced the jeans, the shoes and the shirts [from vintage shops]— which I’m sure he loved.”

One exception is a shocking-pink bathrobe Versace wears to breakfast at his Miami villa on the morning he’s murdered by Andrew Cunanan (Darren Criss). Eyrich had this made to Murphy’s specifications — she says the producer requested something with some “float” in it, so she used an especially lightweight silk. “When Edgar walked, it billowed,” Eyrich says.

Eyrich relied on her “genius tailor” Joanne Mills to remake a dress Versace designed for his sister — a sexy, black leather number accentuated with a series of men’s leather belts linking the bodice to a choker.

“We got every photo we could of [the original] dress,” Eyrich says of the frock that Donatella wore to a party at the New York Public Library celebrating Vogue’s centennial in 1993. “We were very careful to show our utmost respect; I didn’t want to make it look like a made-for-TV movie [design]. I want to pay tribute but not ever minimize. Joanne recreated all the hardware — the belt buckle — and made the full-leather skirt.”

Eyrich and her team also created a whopping 17 looks for a pivotal scene at Versace’s final haute couture fashion show in Paris in 1997, which plays out, in flashback, in the second episode, which airs Jan. 24. Donatella argues with her brother about the direction of their company and needles him about not being able to keep up with younger designers John Galliano and Alexander McQueen.

“You were the future, once,” she says snidely. Ever defiant, Versace tells his younger sister that great design comes “from the heart.” He reduces her to tears of shame with a runway show that unveils one inspired creation after another: A sleek, white evening gown slit up the side, a glittering red minidress and the pièce de résistance — a metallic mesh mini “wedding dress” covered with crosses, worn with a silver-headband veil. The daring piece is for the “Versace bride,” Gianni declares, not a “virginal” one.

“He had this rock ’n’ roll approach to couture,” Ramirez has said. “At this level, in high fashion, he mixed sexuality and glamour, something that, until he came along, were on two different tracks.”

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