Developer is the quiet half of every color formula. The shade in the tube decides the tone, but the developer decides how much the hair lightens, how fully gray is covered, and how much stress the hair takes along the way. Pick the wrong volume and you get hot roots, banding, brassiness or a client whose ends feel like straw. This guide explains what each volume does and how to choose one for the service in front of you.
Key takeaways
- Developer is stabilized hydrogen peroxide. 10 vol = 3%, 20 vol = 6%, 30 vol = 9%, 40 vol = 12%.
- Higher volume means more lift, not better gray coverage. Most permanent lines cover gray with 20 volume.
- Lift depends on the product too. Wella’s Koleston Perfect, for example, gives about 1, 2 or 3 levels with 6%, 9% or 12%.
- Always use the ratio and developer the color brand specifies, and do an allergy alert test 48 hours before every color service.
What developer is (and what “volume” means)
Developer, also called oxidant or peroxide, is a cream or liquid that contains stabilized hydrogen peroxide. Mixed with oxidative color or lightener, it does two jobs at once: it lightens the hair’s natural pigment, and it “develops” the dye molecules so they grow large enough to stay trapped inside the hair.
“Volume” describes strength. It refers to how many volumes of oxygen the peroxide can release, and it maps neatly onto percentage:
| Volume | Peroxide | What it does | Typical services |
|---|---|---|---|
| 5–7 vol | 1.5–2% | Deposit only, very gentle | Demi-permanent color, glosses and toners that come with their own low-volume activator |
| 10 vol | 3% | Deposit with little to no lift | Same level or darker, toning, fragile or porous hair |
| 20 vol | 6% | About 1 level of lift (up to 2 in some lines) | Gray coverage, root touch-ups, most everyday permanent color |
| 30 vol | 9% | About 2 levels of lift (up to 3 in some lines) | Lifting natural hair with permanent color; off-scalp lightening with care |
| 40 vol | 12% | About 3 levels of lift, more with high-lift blondes | High-lift color on healthy, resistant hair; usually off the scalp only |
How much lift should you expect?
The level chart above is a starting point. Real lift depends on the whole system: the color line, the mixing ratio, time, heat, the starting level and the condition of the hair. Manufacturer instructions are the only reliable number.
Wella’s published instructions for Koleston Perfect show how this works in practice. Standard shades mix 1:1 with Welloxon Perfect: 6% gives one level of lift and gray coverage, 9% gives two levels, 12% gives three, and 4% is used on the same depth or darker. The Special Blonde shades mix 1:2 with 12% and reach four to five levels, with a longer 50–60 minute development instead of 30–40 minutes (Wella fact sheet).
So the same “40 volume” can mean three levels in one line and five in another. Treat the table as orientation, not a formula.
Choosing a developer for each service
Gray coverage
Most permanent lines are formulated to cover gray with 20 volume at the brand’s standard ratio. Going up to 30 or 40 adds lift, not coverage, and can leave resistant gray looking brighter or warmer than planned. For stubborn gray, work with the brand’s gray-coverage shades or additives rather than raising the volume.
Same level or darker
Use 10 volume, or the brand’s low-volume option. You do not need lift, so there is no reason to open the cuticle further than necessary.
Toning and glossing
Demi-permanent toners and glazes are usually designed around their own activator, often around 2% peroxide. Paul Mitchell’s the demi, for example, mixes 1:1 with Paul Mitchell Processing Liquid (7 volume, 2%) and processes for up to 20 minutes (The Demi mixing guide; Processing Liquid 7 Volume). Wella Shinefinity mixes 1:1 with a Shinefinity Activator. Swapping in a random 10 or 20 volume changes the result.
Lifting with color
Use 20 volume for about one level, 30 for about two, and 40 only when the hair is healthy, the brand allows it, and you need maximum lift from a high-lift shade.
Lightener (bleach)
Lightener lifts far more than color, so volume is only part of the story: time, product and technique matter just as much. The scalp adds body heat and speeds processing, so many manufacturers limit on-scalp lightening to 20 volume or less. Higher volumes are for off-scalp work such as foils, and only if the lightener’s directions allow it. Lower volume for longer is usually kinder to the hair than high volume for a short time.
Mixing ratios: always follow the brand
Color lines are formulated with a specific developer and ratio in mind. 1:1 is common for permanent cream color, many high-lift and blonding shades use 1:1.5 or 1:2, and demi lines often have their own processing liquid. Mixing the right shade at the wrong ratio can under-deposit, over-lift or change the tone.
- Weigh, don’t eyeball. A small salon scale pays for itself in consistent results.
- Stick to the same brand’s developer when you can. Cream and liquid developers have different consistencies and conditioning agents.
- Mix right before you apply. Wella’s instructions are to apply the mixture immediately. Discard leftovers; never pour mixed product back into a bottle.
Safety and quality checklist
- Allergy alert test. The FDA advises a patch test every time before dyeing hair, and Wella tells stylists to perform one 48 hours before each coloration. See our step-by-step patch test guide.
- Strand test on previously colored, porous or chemically treated hair.
- Wear gloves and keep color away from the eyes.
- Time it. Do not leave color on longer than the directions say. Heat speeds processing.
- Space out chemical services. The FDA recommends waiting at least 14 days after bleaching, relaxing or perming before using dye.
- Store developer capped in a cool place away from sunlight, and rotate older stock to the front.
Stocking developer at the color bar
Most salons keep liters of 10, 20 and 30 volume of their main color line, a smaller amount of 40 volume, and the dedicated activator for any demi or gloss line they use. Label open bottles with the date, and set a minimum stock level so you never run out mid-service. If you need a system for that, our guide on setting minimum stock levels works for hair supplies too.
Shop developer and lightener at OBB
We stock developers and lighteners from professional lines in our Westminster store, including:
- CHI 20 Volume Developer and CHI 40 Volume Developer
- Paul Mitchell Processing Liquid 7 Volume (2%) for the demi
- Wella Shinefinity Activator 2% for Shinefinity glazes
- Lighteners such as Joico Blonde Life, Matrix BlondeMax 9+, Paul Mitchell Blonde and Wella Blondor Soft Blonde 7
Browse everything in Color, Developer & Lightener, or call or text (949) 591-5304 with your list and we will confirm stock and pricing.
FAQ
Can I use 30 volume developer on the scalp?
Only if the color line’s directions allow it. With lightener, many manufacturers cap on-scalp work at 20 volume because body heat speeds processing and raises the risk of irritation and uneven lift.
Does 40 volume cover gray better than 20?
No. Higher volume adds lift. Gray coverage comes from the shade and the brand’s recommended developer, which is usually 20 volume.
Can I mix one brand’s color with another brand’s developer?
It can work, but results become less predictable and you lose the manufacturer’s guidance on timing and lift. For consistent results, use the developer the color line was designed for.
What is the difference between cream and liquid developer?
Cream developers are thicker and stay where you put them, which suits bowl-and-brush application. Liquid developers suit bottle application and some demi and toner lines. Use the type your color line calls for.
Sources
- Wella Professionals, Koleston Perfect fact sheet (mixing ratios, lift per developer strength, allergy alert test)
- U.S. Food & Drug Administration, Hair Dyes
- 365 Salon Group (Paul Mitchell distributor), Product Education: The Demi
- Sullivan Beauty (Paul Mitchell distributor), the demi Processing Liquid 7 Volume
- Wella Professionals, Shinefinity
This article is general education for licensed professionals. Always follow the instructions that come with the product you are using.
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