Since Perry's goal was to enrich Hadid's natural color and remove the red undertones from her last dye job, she chose a demi-permanent dye from Wella . "It's a stain, so it will wash out eventually," Perry explains. "But she wouldn't have to come back into the salon for at least three months." Typically, the lifetime of any hair color depends on the person, their lifestyle, and most importantly, their products. Perry swears by Rahua shampoos and Olaplex for long-lasting color, for the record. Still, if we know anything about Hadid, it's that once she has a look, she keeps it. Expect to see this brunette color long after the glitter is swept off the Victoria's Secret runway.