Overview
Hair coloring is one of the most heavily tested topics on the Illinois Cosmetology State Board Exam. This guide covers color theory, product chemistry, safety protocols, application techniques, and hair analysis — the five core areas you must master. Understanding how these concepts connect will help you apply knowledge correctly under exam conditions.
---
Color Theory
Summary
Color theory forms the foundation of all hair coloring decisions. The color wheel governs how colors interact, how to predict results, and how to correct unwanted tones.
Primary, Secondary & Complementary Colors
• Primary colors: Red, Yellow, Blue — cannot be made by mixing other colors
• Secondary colors: Made by mixing two primary colors in equal parts
- Red + Yellow = Orange
- Red + Blue = Violet
- Yellow + Blue = Green
• Complementary colors: Colors directly opposite on the color wheel; they neutralize each other
| Unwanted Tone | Complementary Neutralizer |
|---|---|
| Orange | Blue |
| Yellow | Violet |
| Red | Green |
The Level System
• Measures depth (lightness to darkness) on a scale of 1–10
• Level 1 = Darkest (black) → Level 10 = Lightest (lightest blonde)
• Higher number = lighter shade
Key Terms
• Tone — The warmth or coolness of a color (ash, golden, red, neutral)
• Level — The degree of lightness or darkness in a hair color
• Complementary colors — Opposite colors on the wheel that neutralize each other
• Contributing pigment (undertone) — Warm pigment revealed as natural melanin is lifted
Watch Out For
> ⚠️ Don't confuse tone and level. Level = how light or dark. Tone = how warm or cool. Exam questions often test these as separate concepts.
> ⚠️ Remember: Blue neutralizes orange (not yellow). Violet neutralizes yellow (not orange). These are commonly swapped on exams.
---
Hair Color Products & Chemistry
Summary
Different hair color types have distinct chemical compositions that determine their ability to lift, deposit, or both. Developer volume controls the degree of lift. Understanding these relationships is critical for safe, predictable results.
Types of Hair Color
| Type | Contains Peroxide? | Lifts? | Deposits? | Fades? |
|---|---|---|---|---|
| Temporary | No | No | Yes (surface only) | After 1–2 shampoos |
| Semi-permanent | No | No | Yes (lightly) | Gradually |
| Demi-permanent | Yes (low volume) | No | Yes | Gradually, no demarcation line |
| Permanent | Yes | Yes | Yes | Does not fade (grows out) |
Developer Volumes
• 10 volume (3%) — Deposit only, minimal lift
• 20 volume (6%) — Standard; 1–2 levels of lift (most common)
• 30 volume (9%) — 2–3 levels of lift
• 40 volume (12%) — Maximum lift (3–4 levels); used with high-lift tints or bleach
Lighteners (Bleach)
• Active boosting agents: Persulfate salts (ammonium, potassium, or sodium persulfate)
• Break down melanin in the cortex
• Used in double-process services to pre-lighten hair
Toners
• Semi- or demi-permanent color applied after pre-lightening
• Applied when hair has been lifted to a pale yellow stage
• Used to achieve the desired final tone (e.g., platinum, pearl, ash)
Mixing Ratio
• Most permanent colors: 1:1 (one part color to one part developer)
• Always follow the manufacturer's directions
Key Terms
• Hydrogen peroxide (developer) — Opens the cuticle; oxidizes color molecules so they penetrate the cortex
• Oxidative color — Any color that requires hydrogen peroxide to develop (demi- and permanent)
• Demi-permanent — Oxidative; fades gradually with no harsh line of demarcation
• Persulfate salts — Active agents in powder lighteners that accelerate melanin breakdown
• Toner — Applied post-lightening to achieve final desired tone
Watch Out For
> ⚠️ Temporary and semi-permanent colors do NOT contain hydrogen peroxide and cannot lighten natural hair. Exam questions may try to blur this line.
> ⚠️ 40 volume is NOT always better. It causes significant damage and is only appropriate for specific services. Knowing when to use each volume is key.
> ⚠️ Demi-permanent IS oxidative (uses very low peroxide) but it does NOT lift — it only deposits.
---
Safety & Client Consultation
Summary
Client safety is non-negotiable. The Illinois State Board places heavy emphasis on patch testing, strand testing, contraindications, and proper record keeping. Know the protocols, timing, and what to do if a reaction occurs.
Predisposition (Patch) Test
• When: 24–48 hours before the color service
• Where: Inside the elbow OR behind the ear
• Purpose: Detect potential allergic reactions to color chemicals (specifically aniline derivative tints)
• Positive reaction signs: Redness, swelling, itching, blistering, eruptions
• If positive: The service must NOT be performed
Strand Test
• Performed on a small section of hair before the full service
• Determines:
- Processing time
- Expected color result
- Hair's ability to withstand the chemical service
Contraindications — Do NOT Apply Color If:
• Client has abrasions, cuts, or scalp irritations (chemicals absorb through open skin → risk of burns, allergic reactions, systemic absorption)
• Patch test showed a positive reaction
Client Record Card — Must Include:
• Client name
• Date of service
• Formula used (product name, shade, developer volume)
• Processing time
• Results / any reactions or notes
Key Terms
• Predisposition (patch) test — Pre-service allergy test applied 24–48 hours before coloring
• Strand test — Pre-service test on a hair section to predict results and timing
• Positive reaction — Signs of allergy; service must be refused
• Client record card — Written documentation of every color service
Watch Out For
> ⚠️ The patch test is 24–48 hours before — not the same day. This is one of the most commonly tested time frames on the board exam.
> ⚠️ A strand test ≠ patch test. The patch test checks for allergies (skin). The strand test checks color results (hair). Know which is which.
> ⚠️ Scalp abrasions or irritations are an automatic contraindication — do not proceed with the service.
---
Application Techniques
Summary
Proper application technique ensures even color results and protects hair health. Application order, sectioning, and tool selection all vary depending on whether you're doing a virgin application, retouch, or specialty service.
Virgin Single-Process Color Application
1. Apply to mid-shaft and ends first
2. Apply to scalp area last
• Why: Body heat at the scalp accelerates processing → scalp processes faster → applying last ensures even color development throughout
Retouch (Touch-Up) Application
• Color applied to new growth only
• Avoids overprocessing previously colored hair
• Prevents overlapping (which causes breakage and banding)
Highlighting Techniques
| Technique | Method | Effect |
|---|---|---|
| Foil highlights | Weaved sections wrapped in foil | Controlled, uniform lightening |
| Balayage | Freehand painting on hair surface | Soft, natural, sun-kissed effect |
Double-Process Color Service
• Step 1: Pre-lighten (bleach) hair to desired level
• Step 2: Apply toner or tint to achieve final desired color
• Used when going significantly lighter than natural color
Key Terms
• Virgin application — First-time color application on uncolored hair
• Retouch — Color applied to new growth only
• Foiling / highlighting — Weaved strands wrapped in foil for controlled lightening
• Balayage — Freehand painting for a soft, natural look
• Double-process — Pre-lightening followed by toning/tinting
Watch Out For
> ⚠️ On a virgin application, scalp goes LAST — not first. Body heat makes it process faster, so it needs less time.
> ⚠️ During a retouch, NEVER overlap color onto previously colored hair. This causes breakage, uneven results, and is a major exam topic.
> ⚠️ Balayage is freehand (no foils). Highlights use foils. The board exam may describe a technique and ask you to identify it.
---
Hair Analysis & Special Considerations
Summary
Hair analysis before any color service helps predict results and prevent damage. Porosity, texture, density, and the presence of gray hair all affect how color performs. Special cases (resistant gray, damaged hair) require modified formulations.
Porosity
• Definition: Hair's ability to absorb moisture and chemicals
• High porosity:
- Absorbs color quickly but releases it rapidly
- Results: Initially darker color → fades faster
- May need a color filler or lower developer volume
• Low porosity:
- Resists color absorption
- May need pre-softening or higher developer
Contributing Pigment (Undertone)
• Warm pigment revealed as melanin is lifted
• Critical for predicting and controlling final color results
• Must be factored into every lightening or color correction service
Resistant Gray Hair
• Hair that is 30% or more gray, especially coarse gray hair, may resist color
• May require:
- Higher developer volume
- Pre-softening the hair before color application
- Longer processing time
Color Fillers
• Used on damaged or overly porous hair
• Replaces missing primary color (usually red/warm tones) before applying new color
• Ensures even, longer-lasting color results
Key Terms
• Porosity — Hair's ability to absorb moisture and chemicals
• Contributing pigment / undertone — Warm tones revealed during the lifting process
• Resistant hair — Hair (often coarse gray) that resists color absorption
• Color filler — Product used to replace missing pigment in damaged/porous hair before recoloring
• Pre-softening — Technique used to open the cuticle of resistant hair before color application
Watch Out For
> ⚠️ High porosity ≠ takes color well permanently. It absorbs fast but fades fast. This nuance is commonly tested.
> ⚠️ Contributing pigment is the #1 reason color corrections go wrong. Always assess undertones before formulating.
> ⚠️ The 30% gray threshold is a key number — know it for the exam.
---
Quick Review Checklist
Use this checklist to confirm you're ready for the exam:
• [ ] I can name the 3 primary colors and the 3 secondary colors
• [ ] I know which complementary color neutralizes orange (blue) and yellow (violet)
• [ ] I understand the level system (1 = darkest, 10 = lightest)
• [ ] I can distinguish between temporary, semi, demi, and permanent color
• [ ] I know which color types contain peroxide and which can lift
• [ ] I know the 4 developer volumes and their lift levels
• [ ] I know the patch test is done 24–48 hours before service
• [ ] I know where the patch test is applied (inside elbow or behind ear)
• [ ] I can identify signs of a positive patch test reaction
• [ ] I know the difference between a patch test and a strand test
• [ ] I know what must be documented on a client record card
• [ ] I know that virgin color goes to mid-shaft/ends first, scalp last
• [ ] I understand retouch application (new growth only, no overlapping)
• [ ] I can distinguish balayage from foil highlights
• [ ] I know what a double-process service involves
• [ ] I understand how high porosity affects color results
• [ ] I know what contributing pigment is and why it matters
• [ ] I know when and why to use a color filler
• [ ] I know the 30% gray threshold for resistant hair
• [ ] I know the standard 1:1 mixing ratio for permanent color
---
Good luck on your Illinois Cosmetology State Board Exam! Focus on safety protocols and color theory — these appear most frequently across exam question banks.