COS is a technology that is the safest and most effective way to remove undesirable hair color. In just 20 minutes, COS corrects and removes the color by shrinking the dye molecules, allowing it to be simply washed out of the hair. Levels are of no concern as COS’s unique bleach and ammonia free formula removes all artificial pigments from the hair keeping the hair in great shape. COS is so gentle that the hair can be recolored right after the COS service. Gently removes oxidative permanent, semi demi permanent hair color Takes only 20 minutes Ammonia bleach free Safe easy Recolor the same day