Details Contain extra pigment for stubborn gray hairs Ultimate gray coverage Add more depth to hair Wella Color Charm Liquid NN Shade Collection Suede Series shades will offer the ultimate in gray coverage without the added warmth. NN shades are for resistant gray/white hair, they contain extra pigment for stubborn coarse hair. NN shades contain more dye molecules so they give more depth to your final hair color result. Directions Mix 1 part CC liquid color with 2 parts CC developer. Apply to the hair using either an applicator bottle or bowl and brush. Develop for 30 minutes and up to 45 minutes if additional depth or gray coverage is desired. Pro Tips Color Charm NN shades can be mixed with other shades to obtain the color you want and the gray coverage you need. NN shades can also be used alone to achieve desired gray coverage. Color Charm NN shades offer the ultimate in gray coverage and should be used for stubborn resistant gray.