Achieve head turning looks with Crazy Color Semi Permanent Hair Dye! Lasting 10-12 washes, it is perfect for mixing up your look. Caution UV is not for the faint-hearted! This yellow UV hair dye which glows in both natural light and blacklight. The conditioning formula makes it easy to apply while hydrating the hair. Does not require peroxide. Works best on pre-lightened hair. A Bleaching Kit is available as part of the Crazy Color® range.