Oligo Calura 4 Neutral Permanent Shine Hair Color Dark Brown 2 Ounce 60 Gram The ultimate grey coverage Oligo Calura hair color is formulated with an innovative exothermic technology that was designed to maximize dye penetration and minimize hair damage. The shade of the color is defined by the specific increase in temperature thus allowing thorough penetration of the certified organic essences and keratin. Gives up to 5 levels of lift. You can find longer lasting fashion shades