Colouring Gray Hair with Curl ID: A Curly Hair Professional’s Guide to Customizing Coverage Without Ammonia
Gray hair is not just a loss of pigment—it signifies a structural transformation that affects how hair behaves, absorbs color, and retains hydration. For clients with curly or highly textured hair, gray coverage must be approached with deep respect for the individuality of each curl strand. At Inhairitance Academy, we’ve developed the Curl ID system to personalize every step of the curl care journey, and that includes gray hair color formulation.
Whether you’re a seasoned stylist or someone coloring your hair at home, this guide will help you understand why coloring gray curls requires much more than choosing 20-volume peroxide and hoping for the best.
What Is Curl ID?
Curl ID is our method of assessing curly hair using four essential parameters:
Curl Size (Diameter)
Elasticity
Porosity
Scalp Health & Absorption Potential
This system allows us to customize everything from pre-color prep to developer strength, ensuring that each curl receives exactly what it needs—no more, no less.
Gray Hair in Curly Clients: What You Need to Know
Gray hair is not uniform. Its texture and response to color can differ drastically based on:
Gray Density – percentage of white vs. pigmented hair (e.g., 10%, 20%, 60%, 80%)
Resistance level – are the grays wiry and coarse or soft and absorbent?
Curl type and porosity – tightly coiled 4C hair will absorb differently than a looser 2C curl
Skin undertones – essential for guiding pigment correction and preventing brassy tones
Common Myths About Colouring Gray Curly Hair
MYTH: You always need 20 volume developer to cover gray.
TRUTH: Not necessarily—especially with non-ammonia-based color. The developer should match the hair’s resistance level and the porosity of the surrounding pigmented strands.
MYTH: Gray is hard to color because it’s coarse.
TRUTH: Some gray hair is fine and soft, especially in early-stage graying (10–20%). It’s not about coarseness, it’s about how resistant the strand is to absorbing color.
Using Curl ID to Customize Gray Coverage
1. Curl Diameter & Developer Strength
Thinner-diameter hair (especially types 2–3a) may not need higher peroxide. These strands open quickly and can oversaturate if the formula is too strong.
Thicker strands in 3c–4c hair may resist color more but are prone to damage if you “force” the color in with harsh developers.
Application Tip: For thicker strands, use alkaline, non-ammonia-based products with longer processing times instead of blasting them open quickly with ammonia.
2. Elasticity & Processing Risk
Low elasticity = high fragility. These curls may snap with excessive peroxide or heat.
High elasticity = better resistance to processing damage, but may be overly porous causing pigment to fade quickly if not properly sealed.
Solution: Conduct an elasticity test. For fragile curls, reduce heat and extend color processing time instead of increasing developer strength.
3. Porosity & Pigment Absorption
High porosity grays will absorb pigment quickly—but fade quickly.
Low porosity grays (typically seen in wiry white hair) resist color and require more processing time, not necessarily more peroxide.
Colour Prep Pro Tip: Use a chelating wash beforehand to remove product buildup, and apply a porosity equalizer on more porous areas.
Decoding Resistance Levels in Gray Coverage
Use the following as a guideline—but always personalize using Curl ID:
(1) Gray Density, (2) Hair Resistance, (3) Suggested Developer, (4) Processing Time
-> (1) 10–20%, (2) Low–Medium, (3) 10–15 volume, (4) 20–30 min
-> (1) 10–20%, (2) High, (3) 20 with 30 volume, (4) 30–35 min
-> (1) 40–60%, (2) Medium, (3) 20 volume, (4) 30–35 min
-> (1) 60–80%, (2) High, (3) 25–35 volume, (4) 30–40 min
-> (1) 100%, (2) Very High, (3) Up to 35 volume (ammonia-free), (4) 40 min (heat optional)
You can “boost” a 20 volume formula by adding 10–15% of 30 volume or use alkaline softening pre-treatments instead of switching to full 30 volume applications.
Pro Tips for Natural, Long-Lasting Gray Coverage on Curly Hair
Avoid ammonia: It blasts the cuticle open too fast. Oil-based, non-ammonia options open slowly, allowing better penetration with less porosity disruption.
Respect curl clumps: Apply color without brushing out the curls, especially in high-density or tight patterns.
Use heat wisely: Only apply gentle heat with a cap if necessary to aid penetration for very resistant grays.
Never skip pH balance: Seal color with an acidic pH shampoo or post-color treatment to lock pigment inside the cuticle.
Hydrate post-color: Curls often lose hydration during the color process. Use hydrating masks to restore softness.
Undertones and Pigment Correction
Your color isn’t just covering gray—it sits beside your natural skin tone every day. Use pigments to your advantage:
Rosacea-prone skin: Avoid reds. Use ash tones with a gold base to neutralize redness.
Cool-toned skin (violet/blue): Use cool ash bases. But balance with warmer neutrals like gold-violet or copper-neutral blends.
Yellow-toned skin: Avoid adding too much gold. Choose neutral or balanced browns and avoid brassy golds.
These principles help balance face and hair without clashing or creating an aged or washed-out effect.
For At-Home Hair Color Clients: What to Know
Stick to professional brands sold at pharmacies or natural health stores.
Choose ammonia-free color systems with permanent and low-volume options.
Always patch test and do a strand test on your grays to assess timing.
Avoid overlapping onto previously dyed hair unless necessary.
Hydration + proper sealing = color that lasts longer and fades beautifully.
Final Thoughts
Curly hair deserves more than a one-size-fits-all color solution—especially when grays enter the picture. With the Curl ID method, stylists and at-home hair color clients can move away from rigid formulas and instead work with the actual properties of the hair. We achieve beautiful gray coverage by understanding resistance, diameter, elasticity, porosity, and pigment—not by rushing in with ammonia and high peroxide.
With time, care, patience, and personalization, colouring gray curls becomes not only effective—but empowering.
Robbins, C. R. (2012). Chemical and Physical Behavior of Human Hair (5th ed.). Springer.
Mirmirani, P., & Stenn, K. (2010). Challenges in the management of hair disorders in patients of color. Dermatologic Clinics, 28(4), 589-600.
Loussouarn, G., El Rawadi, C., & Genain, G. (2005). Diversity of hair growth profiles. International Journal of Dermatology, 44(s1), 6-9.
Jablonski, N. G., & Chaplin, G. (2000). The evolution of human skin coloration. Journal of Human Evolution, 39(1), 57-106.