7.2 Hair coloring & lightening

Reading color: level, tone, and chemistry

Haircoloring changes the natural pigment of the hair or adds artificial pigment. On the exam you must connect three ideas: the level system, the laws of color, and the chemistry that makes color lift or deposit.

The level system

Level is the degree of lightness or darkness of a color, on a scale of 1 (black) to 10 (lightest blonde), regardless of tone. Colorists identify the client's natural level, decide on a target level, and choose a formula and developer that can travel that distance. Moving to a lighter level requires lift; moving darker requires deposit.

The laws of color

• Primary colors — red, yellow, and blue — cannot be created by mixing other colors. Blue is the darkest and only cool primary; yellow is the lightest.
• Secondary colors are equal mixes of two primaries: green (blue + yellow), orange (red + yellow), and violet (blue + red).
• Tertiary colors mix a primary with a neighboring secondary, such as blue-green.
• Complementary colors sit opposite each other on the color wheel and neutralize (cancel) one another: red and green, blue and orange, and yellow and violet.

Tone, or hue, is described as warm (red, orange, gold, yellow) or cool (blue, green, violet). The base tone is the predominant tone of a color. To correct unwanted tones you apply the complement: green neutralizes red, blue neutralizes orange, and violet neutralizes yellow — the reasoning behind purple shampoos and toners on blonde hair.

Natural pigment and contributing color

The natural color of hair comes from melanin in the cortex. Eumelanin produces brown-to-black tones and pheomelanin produces red-to-yellow tones; the mix and amount set the client's natural level. This matters because darker levels hold more warm underlying pigment. When you lift a level, you expose that warmth — the contributing (underlying) pigment — which is why lightening a dark brown almost always reveals red and gold before it reaches yellow. Predicting the underlying pigment at the target level tells you what tone you must neutralize or add to land the desired shade.

Categories of haircolor

Permanent color and lighteners are oxidative: they use small dye precursors that penetrate the cortex and then oxidize into large color molecules that cannot wash out. Resistant gray hair usually needs a permanent color with 20-volume developer for full deposit and coverage, while overly porous hair absorbs color quickly, can grab ash or cool tones, and fades faster — so a filler or gentler formula may be needed.

Developer and the role of ammonia

Hydrogen peroxide developer supplies the oxygen for lift and for oxidizing the dye. Its strength is stated in volume:

Ammonia is the alkalizing agent that raises the pH, swells the hair, and lifts the cuticle so color can enter, and it triggers the peroxide to release oxygen. MEA (monoethanolamine) is a common ammonia substitute in "no-ammonia" lines.

Patch and strand tests

Federal law requires a patch (predisposition) test 24–48 hours before every application of an aniline-derivative (oxidative) color to check for allergy to para-phenylenediamine (PPD). Apply a small amount behind the ear or on the inner elbow; itching, redness, or swelling means do not proceed. A separate strand test predicts the final color and the processing time on that client's hair.

Single- and double-process color

A single-process service lifts and deposits in one application — for example, a permanent single-application tint or a high-lift color. A double-process service takes two steps: first pre-lighten (decolorize) the hair, then apply a toner or color to reach the target shade. Platinum blondes almost always require a double process.

Decolorizing and the stages of lightening

Lighteners work by dispersing and diffusing melanin. As natural pigment lifts, the hair passes through predictable stages of decolorization — the exposed contributing (underlying) pigment:

black → brown → red → red-gold → gold → yellow → pale yellow

The colorist stops at the stage that will support the target shade; going lighter than pale yellow damages the hair. A toner is then applied over the pre-lightened hair to deposit the desired tone and neutralize leftover warmth — a violet-based toner cancels the yellow that remains after lightening. Because lift and tone are separate decisions, always confirm both the target level and the target tone before mixing.