COOL-IT hair mask is specifically formulated to neutralize unwanted warm tones while nourishing the hair and making it softer and silky. Cool-it Mask can be used post-lightening to add cool tones to the hair. COOL-IT Mask has a higher concentration of blue/violet pigments than the shampoo so is therefore stronger. On gold and intense yellow bases to obtain a natural cool result. On yellow bases to obtain very cool results. On light and very light yellow bases to obtain icy ash results.