We use a higher concentration of 100% oxidative dyes to put more color in the hair, providing greater longevity than other brands and fade-proof reds. While delivering extra color molecules to the cortex, the haircolor's unique, cream emulsion delivery system gently elasticizes the cuticle preventing damage. You get intense, long-lasting color and incredible shine. Every shade provides 100% gray coverage so there is no need to add an N series to other shades when covering gray, even with reds, like there is with other brands. Other brands often have a NN series, which simply tells you that there is not enough pigment in the other series.