No longer associated with old age or “giving up”, grey hair is the new blonde, and it's everywhere. Long accepted for men but taboo for women, it's now being embraced by fashion designers and is even taking to the catwalks.

From fashion icons such as Kim Kardashian and Cara Delevingne to manga heroines, it’s even made it into Game of Thrones with Emilia Clarke’s iconic white wig.

Faced with this new craze, brands are developing special ranges and hairdressing salons are offering highly specialised services. An investigation into the roots of this new trend, which is somewhere between a fashion phenomenon and a quest for freedom.