Hair Coloring and Lightening
What this domain tests
Hair coloring and lightening tests color theory, developer selection, patch and strand testing, application order, and safe lifting and depositing.
Core rules
- The level system runs from 1 (black) to 10 (lightest blonde); tone is warm, cool, or neutral.
- Hydrogen peroxide developer volume controls lift: 10 volume deposits, 20 volume lifts about one level, 30 volume about two, and 40 volume about three.
- A patch test is done 24–48 hours before color; a strand test predicts processing and result.
- Lightening reveals underlying pigment: red, red-orange, orange, yellow-orange, and yellow as hair goes lighter.
- Permanent color lifts and deposits; demi-permanent deposits with little or no lift.
- Apply retouch color to new growth first, then refresh ends only as directed.
Worked example
A natural level 5 client wants level 8. That is three levels of lift, so 40-volume developer is generally indicated, but on-scalp sensitivity and manufacturer directions matter. A strand test checks how the hair lifts and which underlying pigment appears before committing.
Traps
Overlapping color; using 40 volume on the scalp without need; skipping the patch test; ignoring porosity; mixing developer with a product not intended for it; forgetting metallic salts.
Exam focus
Connect developer volume to level of lift and predict the underlying pigment exposed.