For centuries the use of hair coloring was restricted to the fashion needs of a privileged few. For a long time, necessity alone dictated its use in hiding white hair to give a more youthful appearance. Today, people in ever-greater numbers-women and men alikechange their hair color to make themselves more attractive. There are various reasons for this: to hide white hair, to lighten hair color or add an additional highlight, to remove the yellow look from gray hair, or to enhance the color of the natural gray, and so on.