Good Dye Young Semi-Permanent Hair Colour This Good Dye Young Semi-Permanent Hair Colour ($18) comes in eight, vibrant shades (plus black), all in an essential oil-rich conditioning cream base. The non-toxic, professional-grade colour will last four to six weeks . . . but is 100 percent free of any harsh peroxide or ammonia. Image Source: sephora.com Good Dye Young Semi-Permanent Hair Colour $18 from sephora.com Buy Now