The number refers to the darkness level. The letter refers to the tone.
natural
golden
copper
red
mahogany
chocolate
ash
Natural (N) shades are ideal for keeping your natural tone.
PRO-TIP: N is best for covering gray hair and giving a natural-looking result. Since gray hairs have lost their natural pigment, they soak up dyes more steadily. That means that brighter color and reds won’t always look natural. If you prefer warm or red tones, mixing with the Natural (N) will give your hair a more uniform result.
