Hair Coloring and Lightening
Hair Coloring and Lightening
This domain tests color theory, level, developer choice, patch and strand tests, application, and lightening safety. The exam emphasizes predictable results and scalp protection.
Core rules
- The law of color: primary colors are red, yellow, and blue; secondary colors are orange, green, and violet. Complementary colors neutralize unwanted tone.
- Level runs from 1 (black) to 10 (lightest blonde). Color cannot lift color; lightening requires a lightener or a higher-lift formula.
- Developer volume controls lift and deposit. In general, 10 volume deposits, 20 lifts about 1-2 levels, 30 lifts about 2-3, and 40 lifts about 3-4; always follow manufacturer instructions.
- Permanent color is usually mixed 1:1 with developer; some high-lift blondes use 1:2. Measure, do not estimate.
- Patch test before aniline-derivative color; strand test before a full application, especially on resistant, porous, or previously colored hair.
Worked example
A client at level 5 wants level 7. A permanent color one to two shades lighter with 20 volume is a reasonable starting point, but a strand test is required. Reason: the client may have hidden porosity or previous color that lifts faster at the ends. If the strand test shows warmth, tone with the complementary color rather than increasing developer volume. Increasing volume would add lift and scalp irritation without guaranteeing the target tone.
Traps
- Treating higher developer volume as thicker or stronger in the same way as color.
- Overlapping color on previously lightened hair.
- Skipping the patch or strand test.
- Mixing peroxide with metallic or unknown products.