Two-time Academy Award–winning costume designer Jenny Beavan, who designed the clothes worn in Mad Max: Fury Road and A Room With a View, was the film's sartorial mastermind.
In fact, she described the project as "the biggest film I'd ever done" since Emma Stone had 47 costume changes and Emma Thomspon, 33.
"It was very important to me for Cruella to be black, white, grey and red," she said.
Jenny added in a press event that since she was "around in the ’70s", she remembered the looks from 40 years ago.
"I remember what people were wearing and there were some wonderful things that came back to me in the process of exploring wonderful photographs and fashion magazines from that time," she said.
"And there was quite a dense script, and you see a complete arc of her journey – from being a young kid who’s rebellious and obviously enjoys clothes, to a fully fledged, very individual type of fashion designer.”
Director Craig Gillespie added: “Fashion was omnipresent in this film. So we got Academy Award-winner Jenny Beavan. She’s done it all. The Baroness is at the height of fashion in the 1970s. How is Cruella going to disrupt the establishment?”
Emma Stone confessed: “The sheer luck of a movie like this is that the costumes do a lot of your work for you as an actor. Once you put those things on, you feel like Cruella de Vil."
The film's lead actress added that when she was all dressed up in her costumes, she couldn't resist channelling her character.
"To first see the entire look of Cruella together, I have to admit I took a lot of pictures.
"It was a very narcissistic day, which is perfect for Cruella!
"Jenny has created something really special."
As for their favourite looks from the film? Both Emmas are in agreement.
"I love the one that she wears on the back of the garbage truck," Emma Thompson told Variety.
"The thing I loved about it was it was real. This skirt was actually attached, it wasn't CGI'd. They drove off fast and it did that amazing fishtail thing for real on camera and I was there to see it and it was epic!"
The hair and makeup is just as iconic as the clothing.
"Emma Stone’s character is more of a punk and influenced by that fashion whereas the Baroness, Emma Thompson has perfected her look in the 1950s/60s, so it meant that we had a whole range of styles to draw from," she explained.
"[We created] lots of pulled back, not a hair in place, sculpted styles."