Mermaid-hued hair in shades of aquamarine, turquoise and cerulean might have been a major trend on Instagram for some time but now it's become high fashion.
That's right - fashion's biggest name, Karl Lagerfeld, sent his models - who included Gigi Hadid, Kendall Jenner and Kaia Gerber - down the Fendi runway yesterday sporting faux-fringes dyed in the dreamiest under-water colours, meaning this trend has officially got fashion's seal of approval.
The man behind the looks was noneother than celebrity hair stylist Sam McKnight, who was inspired by makeup artist Peter Phillips use of green and blue winged eyeliner.
'During the makeup test to figure out the look for the show, Peter had an array of liner marks on the back of his hand that were all sorts of greens and blues,' McKnight told Allure, 'So we decided to dye the hair pieces in similar tones.'
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To create the shimmery, multi-tonal colours, McKnight used a trick that he'd learnt from a previous show, Chanel Cruise 2013.
'The secret is to add black and gray [dye] to the hair,' McKnight explained. 'The black or gray kills the neon that's in the dye. We discovered the trick when we did those pastel wigs for the show at Versailles. The hair color we used for those wigs was too bright — the fabrics were not like that, they were more subdued — so we added drops of black and gray hair dye to water and dipped the wigs in.'