Color Theory
What undertone is exposed when lifting natural level 4 hair to a level 7?
Red-Orange
What’s the primary undertone at level 6?
Red-Orange
What’s the difference between demi-permanent and semi-permanent color in terms of developer use?
Demi uses low-volume developer; semi requires no developer.
What would you use to correct blue-green hair caused by chlorine?
Clarifying treatment followed by red/orange color fill.
A client says her blonde always looks yellow. What questions should you ask first?
Home care, toning schedule, water quality, and heat styling habits.
Define “contributing pigment.”
The natural underlying pigment revealed when lightening hair.
How would you tone a level 10 that pulled pale yellow?
What chemical is used in permanent color to swell the cuticle?
Ammonia (or MEA in ammonia-free formulas)
A client wants to go from level 3 to platinum blonde in one session. What’s your professional response?
It may take multiple sessions to maintain hair integrity.
A new client insists on using box dye. How do you educate them without being offensive?
Explain differences in formulation, developer, and results with professional color.
What’s the result of layering ash toner over violet underlying pigment?
A dull, muddy tone due to over-cooling.
Name a level and tone combo that would look overly brassy on olive skin.
Level 7 Warm/Gold
What’s the result of mixing 40 volume developer with a high-lift color and applying it to level 5 hair?
Warm level 7–8 at best; not enough lift for platinum.
What is the most common cause of color fading in high-porosity hair?
The cuticle is too open to retain pigment.
What’s the best approach when a client’s hair is uneven from at-home lightening?
Strand test, tone uneven areas separately, prioritize hair health.
Why is understanding complementary colors critical in formulation?
To neutralize unwanted tones and achieve balance.
What tone would you use on level 8 hair to achieve a champagne blonde?
Violet-gold (balanced warm and cool)
Why is porosity important in hair color formulation?
It affects how the hair absorbs and holds pigment.
Why must you fill the hair when going from blonde to dark?
To replace missing underlying pigments and prevent muddy/green results.
A client says their grey coverage fades after 2 weeks. What might be the issue?
Resistant grey, wrong developer strength, poor saturation.
Explain simultaneous contrast and how it affects hair color perception.
Colors look different depending on surrounding tones (e.g., neutral beige can appear warmer next to ash).
Why do cooler tones appear darker than warmer tones at the same level?
Cool tones absorb more light, making them appear deeper.
What happens if the pH of a color formula is too low?
Cuticle won’t open, resulting in poor color penetration.
A client’s hair is lifting unevenly—warm at the roots and cool through the ends. What’s causing this, and how would you fix it?
The heat from the scalp causes roots to process faster, leading to “hot roots.” To fix it, apply a cooler formula at the root or adjust developer strength. Tone uneven areas separately, or pre-tone if needed to balance before final toning.
A client wants vivid red but has years of black box dye buildup. What’s your game plan?
Color removal, strand test, possibly multiple lift sessions, then deposit vivid.