Take your shade and color formulas to the next level by adding your desired Color Boost. For a boost of tonality, the suggested dosage is 1 full dose of the dropper per 2 oz. of color chosen. Example: 1 full dose per bottle of color (2 oz.) or ½ a dose per half bottle of color (1 oz.). No extra ColorLush Developer is required. The more Color Boost you add, the more incremental the deepening in level and tonality.