Karlie Kloss was "dead set" on going platinum blonde.

The 24-year-old supermodel showed off her new hue in Paris earlier this week and her colourist Christina Cessna has revealed it took three hours and a lot of care to get her hair's new white tone.

Christina told Us Weekly magazine: "She came in dead-set on platinum!"

"Her colour had previously been lifted a little and her ends had been balayaged [hand-painted], and we had to get all the colour out."

Lightening Karlie's colour took several rounds of bleach and Olaplex treatments, which keeps strands strong as they are coloured.

The hair expert then treated the model's locks with Kerastase Nutritive MasquIntense and advised her to use it in place of her regular conditioner from now on.

Karlie recently admitted she had been dismissed as both "too fat and too thin" at castings on the same day.

"I was called both too fat and too thin by a casting agent on the same day."

However, she was adamant she was not going to be affected by the comments about her appearance, and just wants to focus on her own happiness by remaining strong and healthy.

She explained: "I don't want to please anyone but myself."

Although Karlie has graced the runway for prestigious fashion houses including Victoria's Secret, Elie Saab and Yves Saint Laurent, she has admitted her coding scheme Kode with Klossy is at her "core".

Speaking about her other platforms, she said: "But at my core, I am totally a nerd. I love understanding how things work."

And Karlie is not bothered computer science is not the "sexiest thing" in the world to do, but she is "passionate" about the area.

She added: "[It] is not the sexiest thing [but] I am so passionate about it, and it is genuine."