Colorimetry: The Science of Hair Color
Colorimetry is the most technical and potentially litigious part of hairdressing. It requires understanding the Color Wheel and the underlying pigments of hair.
The Level System
Hair color is measured on a scale of 1 (Black) to 10 (Pale Blonde). When lifting (lightening) hair, you expose the Underlying Pigment.
- Levels 1-4 expose Red.
- Levels 5-7 expose Orange.
- Levels 8-10 expose Yellow.
To get a neutral blonde, you must neutralize that yellow.
Complementary Colors
Colors opposite each other on the wheel cancel each other out.
- Green neutralizes Red.
- Blue neutralizes Orange.
- Violet neutralizes Yellow.
Example: If a client’s blonde hair looks too yellow (brassy), you use a Violet toner.
Developer (Peroxide)
The catalyst that activates the color.
- 10 Vol: Deposits color only (going darker).
- 20 Vol: Lifts 1-2 levels and covers gray.
- 30 Vol: Lifts 2-3 levels.
- 40 Vol: Lifts 3-4 levels (High risk of damage).
High-Value Services: Balayage & Correction
French for «to sweep.» A freehand painting technique that creates a natural, sun-kissed look with soft regrowth lines.
- Why it pays: It is custom, artistic work that cannot be replicated by a box dye. It commands premium pricing ($200+).
- Technique: Paint the surface of the strand (V-shape) and saturate the ends. Use clay-based lighteners that don’t bleed.
Profitable Treatments: Hair Health
Treatments are excellent add-ons or standalone services with high margins.
| Treatment | Purpose | Mechanism | Ideal Client |
|---|---|---|---|
| Keratin | Smoothing & Frizz Reduction. | Coats the hair shaft with protein, sealed by heat. Semi-permanent (3-5 months). | Clients with unmanageable, frizzy, or curly hair wanting smoothness. |
| Botox Capilar | Deep Conditioning & Anti-Aging. | Fills in broken spots in the cortex with vitamins/lipids. Does NOT straighten. | Clients with damaged, processed, or thinning hair. |
| Olaplex/Bond Builders | Structural Repair. | Re-links broken disulfide bonds inside the hair caused by chemical damage. | ANY client getting bleach or color services. |
Business Tip: Always offer a "Bond Builder" add-on with every bleach service. It's an insurance policy for the hair and extra profit for you.