Permanent color contains chemicals like ammonia, which is what opens the cuticle by raising the pH of the hair. Developer—a liquid oxidizing agent that contains hydrogen peroxide—also helps ...

After using a semi-permanent dye, you're going want to keep your color as bright and saturated as possible. The most effective way to do so is using color-safe hair products.

Josh Wood Copper Gold Hair Gloss is a hydrating copper semi-permanent treatment mask that gives hair a far more understated glow than the vivid packaging implies. £15.00 Shop Now ...