THERE are several hair colour products on the market today. Some are designed to complement your hair by coating the cuticle, which acts as a protection to the cuticle. Some penetrate the cuticle and change your hair colour from the first application. Some are best to cover gray hair. You must have a good understanding of the different categories of hair colour, in order to obtain the best results, while ensuring that your hair is left in a stable condition. To know more about the different categories of hair colour click here.