4.3 Hair Coloring and Lightening Principles

4.3 Hair Coloring and Lightening Principles

Haircoloring is one of the most popular and creative services in the salon, but it is also one of the most scientific. Successfully coloring hair requires a thorough understanding of the Law of Color, the haircolor level system, the chemistry of different haircolor classifications, and the proper selection of developers. Florida cosmetologists must master these principles to achieve predictable, safe, and beautiful results for their clients.

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The Law of Color

The Law of Color is a system for understanding color relationships. When coloring hair, you are combining the client's natural pigment with artificial color, which requires a precise understanding of how colors interact.

stateDiagram-v2
    [*] --> Primary_Colors: Yellow, Red, Blue
    Primary_Colors --> Secondary_Colors: Mix Primaries (Green, Orange, Violet)
    Secondary_Colors --> Tertiary_Colors: Mix Primary + Secondary
    Tertiary_Colors --> Complementary_Colors: Opposites Neutralize (e.g., Blue + Orange = Brown/Gray)

Primary Colors

Primary colors are pure colors that cannot be created by mixing other colors. The three primary colors are:

• Blue: The strongest and only cool primary color. Blue brings depth or darkness to any color and absorbs light.
• Red: The medium primary color. Red adds warmth and is the key tone in many copper and auburn formulations.
• Yellow: The weakest primary color. Yellow adds brightness and lightens formulations.

Secondary Colors

Secondary colors are created by mixing equal parts of two primary colors:

• Green (Blue + Yellow)
• Orange (Red + Yellow)
• Violet (Blue + Red)

Tertiary Colors

Tertiary colors are created by mixing equal parts of a secondary color and its neighboring primary color. They are written as primary-secondary combinations: red-orange, yellow-orange, yellow-green, blue-green, blue-violet, and red-violet.

Complementary Colors

Complementary colors are primary and secondary colors positioned directly opposite each other on the color wheel. When mixed together in equal parts, they neutralize each other, creating a neutral brown or gray:

• Blue and Orange neutralize each other.
• Red and Green neutralize each other.
• Yellow and Violet neutralize each other.

In salon services, complementary colors are vital for correcting unwanted tones. For example, if a client's lightened hair has an unwanted brassy orange tone, the cosmetologist applies a blue-based toner to neutralize the orange.

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The Level System and Tone

The Level System

The Level System is a scale used by cosmetologists to analyze the lightness or darkness of a hair color. Levels are numbered from 1 to 10:

• Level 1 is the darkest (true black).
• Level 10 is the lightest (extra light blonde).

During a hair coloring service, the cosmetologist must first identify the client's starting natural level and the target level to determine if the hair needs to be lightened (lifted) or darkened (deposited).

Tone (or Hue)

Tone is the balance of color. It answers the question of what hue is visible in the hair. Tones are categorized as:

• Warm Tones: Colors that reflect light and look warmer (reds, oranges, yellows). These are often described as gold, auburn, copper, or honey.
• Cool Tones: Colors that absorb light and look cooler (blues, greens, violets). These are often described as ash, platinum, or smoky.
• Neutral Tones: A balanced mix of warm and cool tones, lacking dominant warm or cool reflections.

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Classifications of Haircolor

Haircolor products fall into four main categories based on their chemistry and durability:

Permanent Haircolor and Aniline Derivatives

Permanent haircolor is the only classification that can lift (lighten) and deposit color in a single process. It contains uncolored dye precursors called aniline derivatives. These tiny molecules easily penetrate the hair cuticle and enter the cortex.

When mixed with a hydrogen peroxide developer, the aniline derivative molecules undergo an oxidation reaction, combining to form large, colored molecules that become permanently trapped inside the cortex. Because this chemical reaction occurs inside the hair shaft, it cannot be washed out by shampooing.

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Hydrogen Peroxide Developers

A developer is an oxidizing agent (usually hydrogen peroxide, $H_2O_2$) that supplies the oxygen necessary to activate the uncolored dye molecules in permanent haircolor and disperse natural melanin pigment. The strength of hydrogen peroxide is measured in two ways: volume (volume of oxygen gas released) and percentage (concentration of hydrogen peroxide in water).

• 10 Volume (3% Hydrogen Peroxide): Used when less lift is desired and the goal is primarily to deposit color or refresh existing haircolor.
• 20 Volume (6% Hydrogen Peroxide): The standard developer strength. It provides 1 to 2 levels of lift and is the optimal choice for achieving complete gray coverage.
• 30 Volume (9% Hydrogen Peroxide): Used for additional lift, providing 2 to 3 levels of lightening.
• 40 Volume (12% Hydrogen Peroxide): Used with high-lift blondes to provide maximum lift (up to 4 levels). It must be used with caution, as high concentrations of hydrogen peroxide can damage the hair structure and irritate the scalp.