From Kelly Osbourne to Rihanna; celebrities rock rainbow hair as ‘Crayola-colour’ hair dye tops the beauty charts on eBay

eBay, one of the world’s largest marketplaces, has seen an astonishing rise in the sales of  pastel and vibrant coloured hair dye thanks to the likes of Rihanna, Katy Perry and Kelly Osbourne adopting the technicolour trend.