Hair coloring

Hair coloring is the practice of changing the color of hair. The main reasons for this practice are cosmetic (e.g., to cover gray hair, to change to a color regarded as more fashionable or desirable, or to restore the original hair color after it has been discolored by hairdressing processes or sun bleaching). Hair coloring can be done professionally by a hairdresser or independently at home.Today, hair coloring is immensely popular, with over 75 percent of American women dyeing their hair. At home coloring in the United States reached $1.9 billion in the year 2011, and is expected to raise to $2.2 billion by 2016.

https://en.wikipedia.org/wiki/Hair_coloring