Hair Coloring and Lightening
Color theory and law
The law of color: primary colors (red, yellow, blue) combine into secondary colors (orange, green, violet), which combine into tertiary colors. Complementary colors neutralize: blue cancels orange, violet cancels yellow, green cancels red. Trap: choosing a color that reinforces an unwanted tone instead of neutralizing it.
Products and chemistry
Temporary color coats the cuticle; semi-permanent deposits without lifting; demi-permanent uses low-volume developer; permanent color lifts and deposits, requiring developer. Lighteners (bleach) lift pigment without depositing. Developer (hydrogen peroxide) volume controls lift: 10 volume deposits, 20 volume lifts one to two levels, 30 volume more, 40 volume maximum. Trap: using high-volume developer on the scalp or on damaged hair.
The color wheel in practice
Determine the natural level (1 black to 10 lightest blonde), the desired level, and the underlying pigment. Fill before coloring when going darker on lightened hair. Strand test before any chemical service.
Safety
Patch test 24-48 hours before color; never mix developer in metal bowls; wear gloves; ventilate. Do not color over compromised scalp or after a fresh relaxer without guidance.
Worked rule of thumb
"Lift first, then tone; neutralize the underlying pigment." If hair lifts to yellow-orange, tone with blue-violet to reach a neutral blonde.