Acidic vs Alkaline Hair Color: What’s the Difference for Professional Hair Stylists
- What is Alkaline Hair Color
- What is Acidic hair Color
- Why pH Level Matters: How It Affects the Overall Color Result and Hair Feel
- Is Acidic or Alkaline Better for Your Hair?
- Caring for Hair After Using Alkaline Hair Color
- • The difference between alkaline and acidic hair color hinges on pH and its effect on the hair cuticle.
- • Alkaline color systems gently open the cuticle to allow lift and create a lasting color change, making them ideal for roots and gray coverage.
- • Acidic color systems keep the cuticle compact, depositing tone and enhancing shine with a more conditioning experience, which is well suited for mid-lengths and ends.
For professional hair stylists, understanding the difference between acidic and alkaline hair color is essential for mastering color chemistry, delivering predictable results, and maintaining hair health. These two types of hair color differ primarily in their pH levels, which influence how they interact with the hair cuticle, the type of color change they create, and how the hair feels after the service.
This article explains the key distinctions between acidic and alkaline hair color and outlines how Redken’s modern color innovations, including Shades EQ and the new Shades ALK, are designed to deliver high-performance results while respecting hair integrity.
WHAT IS ALKALINE HAIR COLOR: LIFT, PENETRATION, AND COVERAGE
Alkaline hair color has a pH above 7. This elevated pH causes the hair cuticle to swell slightly, allowing color molecules to penetrate into the cortex of the hair.
FUNCTION
Alkaline color systems are used when lift, gray coverage, or a lasting change to natural pigment is required. They allow stylists to:
- Lift natural pigment
- Deposit longer-lasting color
- Create visible and durable color change at the root
EFFECT ON HAIR
Traditional alkaline permanent color systems rely on strong cuticle opening, which can place stress on the hair structure when aggressive lift is required. Modern alkaline demi-permanent systems like Shades ALK are designed to deliver controlled, low-level lift while supporting hair integrity during processing.
EXAMPLE: SHADES ALK
Redken's Shades ALK is a new-generation alkaline demi-permanent color that offers:
- Up to one level of lift
- Up to 75 percent gray coverage
- No ammonia
- A conditioning hydro-magnetic system designed to maintain hair health during application
Unlike traditional permanent color, Shades ALK creates a lasting change to natural hair pigment with lower lift and a more hair-respecting experience. This makes it ideal for clients who want visible, long-term results without the intensity associated with permanent color services.
Alkaline color is most commonly used on virgin hair and new growth, also known as Zone 1, where lift and coverage are most needed.
REDKEN ALKALINE COLOR LINES: Color Fusion, Cover Fusion, Color Gels Lacquers, Color Gels 10 Minute Color, Color Gels Oils, and Shades ALK
WHAT IS ACIDIC HAIR COLOR: GENTLE DEPOSIT, SHINE AND CUTICLE CARE
Acidic hair color has a pH below 7. These formulas work closer to the hair’s natural pH and cause minimal cuticle swelling, allowing color to deposit while keeping the cuticle compact and smooth.
FUNCTION
Acidic hair color is designed to:
- Deposit tone without lifting natural pigment
- Enhance shine
- Improve the overall look and feel of the hair
EFFECT ON HAIR
Because acidic formulas keep the cuticle largely closed, they are known for being exceptionally gentle and conditioning. They help smooth the hair surface, increase light reflection, and support long-term hair health.
EXAMPLE: SHADES EQ
Redken’s Shades EQ is an iconic acidic demi-permanent gloss and toner that enriches tone, enhances shine, and improves hair condition. It is ideal for mid-lengths and ends, also known as Zones 2 and 3, where hair is often more porous or previously colored.
Acidic hair color is best suited for refreshing color, toning, and enhancing shine on previously colored or sensitized hair.
REDKEN ACIDIC COLOR LINES: Shades EQ Gloss
WHY PH LEVEL MATTERS: HOW IT AFFECTS THE OVERALL COLOR RESULT AND HAIR FEEL
pH plays a critical role in both immediate color results and the long-term condition of the hair.
CUTICLE BEHAVIOR
Alkaline environments with a pH above 7 allow the cuticle to open so color molecules can penetrate and create lasting change. Acidic environments with a pH below 7 help tighten the cuticle, smoothing the hair surface and locking in shine.
LIFT VERSUS DEPOSIT
Alkaline formulas enable lift and longer-lasting color change, while the level of lift and intensity varies by formulation. Acidic formulas do not lighten hair but excel at depositing tone and enhancing gloss.
COLOR LONGEVITY AND VIBRANCY
Maintaining proper pH balance supports color longevity and vibrancy. Acidic glosses and aftercare products, such as Shades EQ services and Redken Acidic Bonding Concentrate haircare, help rebalance the cuticle after color services and enhance shine.
HAIR CONDITION
Modern color systems are designed with pH management in mind. Controlled alkaline processing paired with acidic finishing services and home care allows stylists to achieve impactful color results while maintaining hair integrity.
IS ACIDIC OR ALKALINE BETTER FOR YOUR HAIR?
Neither acidic nor alkaline hair color is inherently better. Each serves a specific role in professional color services.
ALKALINE COLOR:
Alkaline color is best for lifting natural pigment, creating lasting color change, and providing gray coverage. Low-lift alkaline demi-permanent systems like Shades ALK offer these benefits with significantly less structural stress than traditional permanent color, making them ideal for clients who want durability without intensity.
ACIDIC COLOR:
Acidic color is ideal for toning, glossing, and refreshing color while maintaining optimal hair condition. These formulas enhance shine and are best suited for previously colored hair and more fragile areas.
Professional color services often combine both approaches to achieve balanced, healthy-looking results.
Redken’s approach mirrors this ideal balance, using zone applications and products like Shades ALK for alkaline lift at the roots and Shades EQ for acidic gloss and tone on the lengths and ends. This allows stylists to maximize color impact while maintaining hair health.
CARING FOR HAIR AFTER USING ALKALINE HAIR COLOR
After an alkaline color service, proper aftercare supports hair health, shine, and color performance.
- USE ACIDIC PH AFTERCARE PRODUCTS: Acidic conditioners, glosses, and treatments help rebalance the cuticle and enhance shine. Redken’s Acidic Bonding Concentrate haircare line and Acidic Color Gloss services are designed to support strength, smoothness, and color longevity.
- MAINTAIN MOISTURE: Nourishing masks and leave-in treatments help sustain softness and manageability. Products like the Acidic Bonding Concentrate Leave-In Treatment provide lightweight conditioning and protection between salon visits.
- CHOOSE GENTLE CLEANSERS: pH-balanced shampoos formulated for color-treated hair help preserve vibrancy and maintain hair condition.
- PROTECT FROM HEAT: Minimize excessive heat styling and always use heat protection to support long-term hair health.
- SCHEDULE MAINTENANCE SERVICES: Regular glossing and conditioning treatments help maintain vibrant, healthy-looking hair between appointments.
Integrating these care steps after alkaline coloring supports hair resilience, maintains color intensity, and ensures client satisfaction with both look and feel.
The difference between alkaline and acidic hair color hinges on pH and its effect on the hair cuticle. Alkaline color systems gently open the cuticle to allow lift and create a lasting color change, making them ideal for roots and gray coverage. Acidic color systems keep the cuticle compact, depositing tone and enhancing shine with a more conditioning experience, which is well suited for mid-lengths and ends. Redken’s innovative products like Shades ALK and Shades EQ reflect this balance, giving professional stylists the tools to deliver impactful color results while maintaining hair health.
By applying pH science through Redken’s zone-based color approach, stylists can create vibrant, durable color services that look beautiful and feel healthy.