Wella Color Charm Creme Developer is specially stabilized for use with all permanent hair colors. Great for covering white/gray hair or lightening natural hair color. Use whenever coloring directions call for 40 volume developer. Wella® ColorCharm® 40 Volume Creme Developer is formulated specifically for ColorCharm® haircolor. Provides proper level of activation for effective color deposit without lift. Specially stabilized for use with all permanent haircolors. Great for covering white/gray hair or lightening natural hair color.