Biosky Color Mask is a regenerating color mask to intensify the color of natural, colored and streaked hair and is ideal for reviving the color between one color and the next one and to illuminate with intense reflections whenever the hair is dull, opaque and lacking in vitality. Enriched with keratin, collagen, hyaluronic acid and a mix of natural oils for a moisturizing, nourishing, restructuring and strengthening action. (It can cause an allergic reaction.)