Keira Knightley never brushes her hair on her days off. (Photo: Evan Agostini/AP)

Actress Keira Knightley has admitted to 'never' brushing her hair unless she has to work.

The 32-year-old actress' "off-duty" look is more minimal than people would expect, and she rarely even brushes her hair or wears make-up when she isn't filming.

Speaking to she said: "I probably wear a hell of a lot less make-up than when I first started [working]. I really enjoy working with wonderful make-up artists, wonderful hairdressers, and creating a look and fantasy. 

"Then, my off-duty look is literally not even brushing my hair and wearing very little makeup. I'm a girl of extremes but I enjoy both things."

The 'Pirates of the Caribbean' actress has had to change her hair for different roles over the years and her favourite character do was Cecilia's in 'Atonement'. 

She said: "'Atonement', that was a very good one, I love that that hairstyle. I really enjoyed 'Anna Karenina', again, the hair in that was amazing and then 'Colette' coming up this year - she's just f***ing cool. She [French novelist Sidonie-Gabrielle Colette] was breaking boundaries and her look is very much her own creation." 

However, Keira has also had some "terrible" styles thanks to her work.

She said: "When I worked on 'Never Let Me Go', I had such very perfect, fashionable bangs and they were like 'No, this doesn't work at all for the film.' So they just cut my hair in a really wonky way and it looked terrible."

Keira is filming Disney's upcoming movie, 'The Nutcracker and the Four Realms', where she sports a pink wig and glittery skin, and she found the colourful character "really fun" to play. 

"It was really fun. There was a lot of glitter. They actually used prosthetics on my eyebrows so that they could paint my eyebrows on higher, thinner, and purple. Then [I had] very glittery pink nails and, obviously, an enormous wig that was meant to look like - we call it 'candy fluff'...what do you get at circuses? Cotton candy!"