HOLLY Willoughby revealed her biggest hair disaster while showing fans how to dye their own hair at home. The TV star, 39, revealed she accidentally dyed her hair red after experimenting with spray in bleach. "I went red by accident when I was much much younger and you want to experiment with your hair," she told Vogue's beauty and lifestyle director Jessica Diner during a video call. "I'd gone blonde by using one of those beach spray blondes... "So I came back home and was like 'Oh I'd better just put this dark hair dye over the top.' "And obviously, I'm not a colourist but that was disaster, It' didn't go brown it went red.