ABSTRACT
Hair dyes represent a major hair cosmetic used by both men and women. It is estimated that 40% of women regularly use hair dyes to blend gray tones, cover gray hair, add colored highlights, produce unnatural temporary colors, and either lighten or darken the original hair color. Hair dyeing is used to cover gray and achieve a more youthful appearance, but it is also used to change the natural hair color based on personal preference. A number of different hair dye cosmetics have been developed to fulfill all of these needs: gradual, temporary, semipermanent, and permanent. Approximately 65% of the hair dye market is for permanent hair colorings, 20% for semipermanent colorings, and 15% for the remaining types.
