This document discusses various techniques and principles for coloring hair, including: 1) Applying color from roots to mid-length and ends is best for virgin hair to ensure even coverage. Oxidation involves the addition of oxygen to allow coloring and lightening as tint and peroxide break down the hair's natural melanin pigments. 2) The color wheel principle is important - if hair is too red, a color on the opposite side of the wheel like blue is used to tone it. 3) Peroxide aids in darkening, toning, and lightening hair and 40 volume provides maximum lift for tinting. Melanin contains either black/brown eu-melanin pig