calura intense neutral perm coloring 10ga 10 3160ML The CALURA system is formulated with an innovative exothermic technology that has been designed to maximize the penetration of the dyes and minimize damage to the hair. Each shade has been formulated to generate a specific increase in temperature in order to achieve the desired results. As a bonus, this heat allows for a deep penetration of pure organic essences and keratin. The result is an incomparable brilliant shine!