Lily James is a fashion "chameleon".

The 31-year-old actress has been praised by 'Rebecca' costume designer Julian Day for the ease in which she is able to "inhabit" different clothes and show them off to their best, whatever the garment may be.

He said: "Lily is amazing. She's like a chameleon. I've never seen anyone put on clothes and inhabit them so well and really show them off to their best."

Lily relies on her clothes to get into character and Julian - who previously worked with her on 'Pride and Prejudice and Zombies' - knows she needs to "trust" the wardrobe department.

He told Britain's HELLO! magazine: "When you meet an actor, they have to feel confident with you, and with Lily, you have to make her trust you.

"Lily is very much about instinct. We put the brown suit on her and that was it, she became the maid.

"Then we put on a suit and she became the second Mrs. de Winter."

Julian enjoyed transforming Lily's wardrobe as her unnamed character in the thriller gradually changes over the course of the movie.

He said: "When we first see her, she's in a dowdy, hand-me-down brown suit as she's a lady's maid and doesn't have any money.

"But when she starts the blossoming relationship with Maxim, I threw that out of the window as I wanted to create a lovely romantic look with chiffons and lightweight cottons and linens, idyllic tableaux with straw hats.

"I used a lot of Liberty fabrics as they're very romantic, and showed some flesh as well - arms and shoulders, which was quite provocative at the time.

"Then, when we get to Manderely, she starts to take on the persona of the house - the country lady with the twinset and pearls.

"She goes from being a subservient girl to a woman and I wanted to create a much stronger silhouette.

"Her skirts are more fitted, severe and domineering as she's taking more control."