Hair Coloring and Lightening
The level system and the law of color
Natural hair levels run 1 (black) to 10 (lightest blonde), with undertone describing the warmth beneath the surface. Primary colors are blue, red, and yellow; secondary colors (green, orange, violet) are mixes of two primaries. Complementary colors neutralize - blue cancels orange, violet cancels yellow, green cancels red.
Developers and lift
- 10 volume (3%) - deposit only, no lift.
- 20 volume (6%) - lifts about one level and deposits.
- 30 volume (9%) - lifts about two levels.
- 40 volume (12%) - lifts about three to four levels and is the harshest.
Application logic
For virgin hair, apply to mid-lengths and ends first, then the scalp area, because scalp heat accelerates development. For a retouch, apply only to new growth. Always perform a patch test 24–48 hours before an aniline derivative color and a strand test to preview timing. When returning a lightened client to a darker shade, use a filler to replace missing pigment or the result will look muddy or green.
Traps to expect
Questions love to overstate lift ("40 volume lifts six levels") or claim lightener lifts tinted hair as easily as virgin hair - artificial pigment resists lightening. Another trap: assuming a color's name tells you its level; read the number.
Worked example
A client's blonde has gone brassy yellow-orange. Yellow is neutralized by violet, orange by blue - so a blue-violet based toner is the correct family. Rule of thumb: name the unwanted tone, then choose its opposite on the color wheel.