8.1 Color Theory, Law of Color & The Level System
Key Takeaways
- The Law of Color dictates that all colors are created from three fundamental primary colors (blue, red, yellow) that cannot be produced by mixing any other pigments.
- Complementary colors sit directly opposite one another on the color wheel and neutralize each other when blended in proper proportions (e.g., violet neutralizes yellow undertones).
- The universal Level System standardizes hair lightness and darkness on a numerical scale from Level 1 (Darkest Black) to Level 10 (Lightest Platinum Blonde).
- Every natural level contains a specific contributing underlying pigment (undertone) that must be calculated when formulating target shades.
- Accurate formulation requires assessing the client's natural level, existing artificial color, porosity, and exact percentage of unpigmented/gray hair (25%, 50%, 75%, 100%).
Introduction to Color Physics & The Law of Color
Haircoloring is both an artistic discipline and a precise chemical science. For the Pennsylvania State Board of Cosmetology examination, candidates must master the scientific principles governing light, pigment reflection, and chemical dye formulation. The foundation of all color services is the Law of Color, a universal system of physics that explains how colors interact, combine, and neutralize one another.
Visible color exists because light reflects off surfaces at varying wavelengths. Hair pigments absorb certain wavelengths of light and reflect others back to the human eye. When formulating haircolor, a cosmetologist does not simply paint a surface; they combine artificial pigments with the hair's existing natural or synthetic pigments within the cortex to produce a modified visual result.
The Color Wheel: Primary, Secondary & Tertiary Colors
Understanding the spatial and relational positioning of pigments on the standard color wheel is essential for predicting color results and correcting unwanted tones.
YELLOW (Lightest/Weakest Primary)
/ \
Yellow-Green / \ Yellow-Orange
/ \
GREEN ORANGE (Secondary)
(Secondary) /
\ /
Blue-Green \ / Red-Orange
\ /
BLUE -- RED
(Coolest/Darkest) (Medium Warmth)
\ /
Blue-Violet \ / Red-Violet
\ /
VIOLET (Secondary)
1. Primary Colors
Primary colors are pure, fundamental colors that cannot be created by combining any other colors. All other visible hues on the spectrum are derived from combinations of these three primaries:
- Blue: The coolest, strongest, and darkest primary color. Blue is the only cool primary color. It brings depth, darkness, and coolness to any formula. When added to a formula, blue lowers the perceived level of lightness.
- Red: The medium-strength primary color. Red adds warmth, richness, and vibrancy. Adding red to blue-based colors softens their coolness, while adding red to yellow-based colors deepens their warmth.
- Yellow: The lightest and weakest primary color. Yellow adds brightness, lightness, and illumination. It is the easiest primary color to overpower when mixing formulas.
- Equal Primary Balance: Mixing blue, red, and yellow in equal proportions produces black or a neutral dark brown, as all wavelengths of light are absorbed.
2. Secondary Colors
Secondary colors are created by blending equal parts of two primary colors. They sit directly between their parent primaries on the color wheel:
- Green: Produced by mixing equal parts of Blue + Yellow.
- Orange: Produced by mixing equal parts of Red + Yellow.
- Violet: Produced by mixing equal parts of Blue + Red.
3. Tertiary Colors
Tertiary (intermediate) colors are formulated by mixing equal parts of a secondary color with its neighboring primary color on the color wheel. In standard cosmetology nomenclature, the primary color name always precedes the secondary color name:
- Blue-Green (Blue + Green)
- Blue-Violet (Blue + Violet)
- Red-Violet (Red + Violet)
- Red-Orange (Red + Orange)
- Yellow-Orange (Yellow + Orange)
- Yellow-Green (Yellow + Green)
Complementary Colors & Neutralization
Complementary colors are defined as any two colors positioned directly opposite each other on the color wheel. The fundamental rule of complementary color theory is that complementary colors neutralize each other when combined in equal proportions, yielding a neutral brown, taupe, or gray tone.
- Blue and Orange: Complementary opposites. Blue neutralizes orange/brassiness; orange neutralizes unwanted blue tones.
- Red and Green: Complementary opposites. Green neutralizes unwanted red/ruddy tones; red neutralizes green/chlorine casts.
- Yellow and Violet: Complementary opposites. Violet neutralizes unwanted yellow/golden tones; yellow neutralizes violet hues.
State Board Exam Tip: Questions regarding toner selection frequently test complementary color relationships. If a client's hair has been pre-lightened to pale yellow, a violet-based toner must be selected to cancel out the yellow and achieve a cool, neutral platinum blonde.
Tone and Hue Classifications
While level measures the lightness or darkness of a color, tone (also known as hue) describes the balance of color and the warmth or coolness perceived by the eye:
- Warm Tones: Reflect light and appear lighter than their actual level. Warm tones include gold, orange, red, copper, strawberry, and yellow.
- Cool Tones: Absorb light and appear deeper or darker than their actual level. Cool tones include ash, blue, green, violet, smoky, and platinum.
- Neutral / Natural Tones: Exhibit an equalized balance of warm and cool pigments, reflecting light evenly without exhibiting dominant red, gold, or ash highlights.
The Universal Level System & Underlying Pigments
The Level System is the standardized numerical scale utilized by colorists and haircolor manufacturers to classify the degree of lightness or darkness of natural or artificial haircolor. The scale spans from Level 1 (Darkest Black) to Level 10 (Lightest Platinum Blonde).
Underlying Contributing Pigment (Undertone)
Natural hair color is composed of two types of melanin within the cortex: eumelanin (brown and black pigment) and pheomelanin (red and yellow pigment). When hair is chemically lightened or lifted, the dark eumelanin granules are oxidized first, exposing the warm pheomelanin undertones. The exposed tone is called the contributing pigment or underlying pigment.
| Level | Haircolor Classification | Contributing Underlying Pigment (Undertone) | Correcting / Neutralizing Base Tone |
|---|---|---|---|
| Level 1 | Darkest Black | Dark Red-Brown | Green-Blue |
| Level 2 | Very Dark Brown | Red-Brown | Green |
| Level 3 | Dark Brown | Red | Green |
| Level 4 | Medium Brown | Red-Orange | Blue-Green |
| Level 5 | Light Brown | Orange | Blue |
| Level 6 | Dark Blonde | Orange-Gold | Blue-Violet |
| Level 7 | Medium Blonde | Gold | Violet-Blue |
| Level 8 | Light Blonde | Yellow-Gold | Violet |
| Level 9 | Very Light Blonde | Yellow | Violet |
| Level 10 | Lightest Platinum Blonde | Pale Yellow | Pale Violet / Pearl |
Critical Formulation Rule: You must always formulate for the target level by factoring in the underlying pigment exposed at that level. If the target level is Level 7 (Medium Blonde with underlying Gold), using a violet-based base tone will neutralize the gold to produce a natural neutral blonde, whereas using a gold base tone will enhance the warm, vibrant blonde.
Evaluating Natural Hair Level & Gray Percentage
Before selecting or mixing any haircolor formula, the cosmetologist must perform a systematic hair analysis.
Step-by-Step Natural Level Determination
- Take a 1/2-inch square section of hair from the crown or occipital region where hair is least exposed to environmental lightening.
- Match the natural hair strand against manufacturer level system swatch swatches under natural, indirect daylight or color-balanced (5000K) salon lighting.
- Note variations across different zones of the head (new growth, mid-lengths, ends, and hairline).
Evaluating Unpigmented / Gray Hair
Gray hair (technically unpigmented or canities hair) occurs when melanocytes in the hair bulb cease melanin production. Because gray hair contains zero natural pigment, artificial color applied over it will appear entirely transparent or overly vibrant unless balanced with a natural/neutral base.
Percentage of Gray Hair & Formulation Adjustments:
┌─────────────────────┬────────────────────────────────────────────────────────┐
│ Gray Percentage │ Visual Characteristics & Formulation Rule │
├─────────────────────┼────────────────────────────────────────────────────────┤
│ 25% Gray (Slight) │ More pigmented than gray hair; color formulation does │
│ │ not require heavy natural base compensation. │
├─────────────────────┼────────────────────────────────────────────────────────┤
│ 50% Gray (Medium) │ Equal balance of pigmented and unpigmented hair; │
│ │ formulate with 50% Natural/Neutral base + 50% target. │
├─────────────────────┼────────────────────────────────────────────────────────┤
│ 75% Gray (High) │ Unpigmented hair dominates; formulate with 75% │
│ │ Natural/Neutral base + 25% target shade for coverage. │
├─────────────────────┼────────────────────────────────────────────────────────┤
│ 100% Gray (Total) │ Completely unpigmented; formulate with 100% Natural │
│ │ base or 1 level darker than desired target shade. │
└─────────────────────┴────────────────────────────────────────────────────────┘
Which primary color is the coolest, deepest, and strongest, having the physical property of lowering the perceived level of lightness when added to a formulation?
When lightening virgin hair from a natural Level 3 Dark Brown to a Level 8 Light Blonde, which underlying contributing pigment is exposed at the target Level 8?
According to the principles of complementary color neutralization, what tone must be incorporated into a formula to cancel out unwanted brassy orange tones in a client's hair?