Professional Hair Colour Developer Guide
Choosing the right developer is one of the most important parts of any professional colour service. The developer you select can influence lift, deposit, grey coverage, tonal outcome and the overall condition of the hair. For colourists, understanding when to use 5 Vol (1.5%), 10 Vol (3%), 20 Vol (6%), 30 Vol (9%) or 40 Vol (12%) developer is essential for creating predictable, tailored results.
This professional hair colour developer guide explains the role of each volume, when it may be used and the key consultation factors to consider before beginning a service.
5 Vol (1.5%), 10 Vol (3%), 20 Vol (6%), 30 Vol (9%) and 40 Vol (12%) Explained.
What Does Hair Colour Developer Do?
Developer is an oxidising agent used with professional hair colour and lightening products. It activates the colour formula and helps the product perform as intended, whether the goal is depositing tone, lifting the natural base, covering grey or lightening the hair.
Different developer strengths are measured in volume. In general, the higher the volume, the greater the potential for lift. However, higher volume is not always the right choice. The best developer is the one that achieves the desired result while respecting the client’s hair condition, history and service requirements.
Always follow the recommended mixing ratio, development time and professional instructions for the specific OSMO IKON product being used.
5 Vol (1.5%) Developer: For Gentle Deposit and Tonal Refinement
5 Vol developer is commonly chosen when the main goal is minimal lift with maximum tonal refinement. It can be ideal for glossing, refreshing faded colour, enhancing shine and creating subtle tonal changes.
This lower-volume option is particularly useful when working on sensitised, porous or pre-lightened hair where additional lift is not required. It can also be used when the colourist wants to add richness, neutralise unwanted tones or create a soft, sheer finish.
Typical uses for 5 Vol developer include:
Tonal glossing services
Refreshing faded mid-lengths and ends
Adding shine and depth
Soft colour enhancement
Refining pre-lightened hair
Gentle tonal correction
For clients looking for a low-commitment colour refresh, 5 Vol can help create a polished result without unnecessary lift.
10 Vol (3%) Developer: For Deposit, Darkening and Tone-on-Tone Colour
10 Vol developer is often used when the goal is colour deposit with little to no lift. It is a versatile choice for tone-on-tone colouring, darkening, enhancing natural depth and refreshing existing colour.
It can be particularly effective for clients who want to deepen their colour, revive faded lengths or introduce a richer tonal direction. Depending on the colour system and service, 10 Vol may also be used for certain grey-coverage or colour-refresh applications.
Typical uses for 10 Vol developer include:
Deposit-only colour services
Darkening natural or coloured hair
Enhancing depth and richness
Refreshing faded colour
Tone-on-tone results
Colouring porous lengths and ends
When working with 10 Vol, always assess the hair’s porosity. More porous areas may absorb tone more quickly, so formula adjustment and application technique are essential for an even result.
20 Vol (6%) Developer: For Grey Coverage and Moderate Lift
20 Vol developer is one of the most widely used strengths in professional permanent hair colour services. It is commonly selected for reliable grey coverage and moderate lift, often up to around two levels depending on the product, natural base and hair condition.
For many colourists, 20 Vol is a go-to choice when creating permanent colour results that need both coverage and lift. It can be used for a wide range of salon services, including root applications, natural base changes and traditional grey-coverage appointments.
Typical uses for 20 Vol developer include:
Permanent grey coverage
Root colour applications
Moderate lift on natural hair
Natural base adjustments
Standard permanent colour services
When formulating for grey coverage, consider the percentage of grey, the client’s natural base and the desired tonal result. Including an appropriate natural or natural-intense shade may be necessary to achieve balanced, long-lasting coverage.
30 Vol (9%) Developer: For Higher Lift and Brighter Results
30 Vol developer is used when more lift is required than 20 Vol can provide. It is often selected for higher-lift permanent colour services, brighter results on natural hair and certain lightening applications, depending on the product instructions.
This developer strength can be useful for clients looking to lift their natural base while adding a new tonal direction in one service. However, it should be used carefully and only when the hair is in suitable condition for the level of lift required.
Typical uses for 30 Vol developer include:
Higher-lift permanent colour services
Brighter blonde and fashion-colour bases
Lifting natural hair beyond standard coverage services
Selected lightening applications
Creating more visible lift on resistant natural hair
A thorough consultation is essential before using 30 Vol. Consider previous colour history, hair condition, scalp sensitivity and the realistic level of lift that can be achieved in one appointment.
40 Vol (12%) Developer: For Maximum Lift Where Appropriate
40 Vol developer is the highest standard developer strength used in many professional colour systems. It is generally reserved for services requiring maximum lift, such as high-lift colour applications or specific lightening services where the manufacturer’s instructions allow.
Because 40 Vol has a stronger lifting action, it should only be used by trained professionals following the correct product guidance. It is not automatically the best option for achieving a lighter result. In many cases, a more controlled approach using a lower developer strength, appropriate lightening product and careful timing will deliver a better result while helping to protect the hair.
Typical uses for 40 Vol developer may include:
High-lift colour services
Maximum lift on suitable natural hair
Selected off-scalp lightening services
Specialist colour-correction work, where appropriate
Do not use 40 Vol simply to speed up a service. Hair integrity, accurate formulation and controlled development should always take priority over maximum lift.
How to Choose the Right Developer
The right developer strength depends on more than the desired shade. Before formulating, assess the complete picture:
The client’s natural base level
Existing artificial colour
Percentage and resistance of grey hair
Hair condition and porosity
Previous chemical services
Desired level of lift
Desired tonal direction
Product-specific mixing instructions
Whether the application is on-scalp or off-scalp
A strong consultation helps prevent unwanted warmth, uneven lift, compromised condition and unpredictable results.
Developer and Hair Integrity
Developer selection plays a major role in maintaining hair quality. Using a higher volume than necessary can increase the risk of dryness, uneven results and unnecessary stress on the hair. Using the lowest effective developer strength for the desired outcome is often the best approach.
For lightening and colour-correction services, incorporate appropriate professional care and bond-supporting products where required. This helps support the hair throughout the service and creates a better foundation for the final tonal result.
Create More Predictable Colour Results with OSMO IKON
Professional colour results begin with accurate consultation, thoughtful formulation and the right developer choice. Whether you are creating a soft gloss with 5 Vol, covering grey with 20 Vol or achieving a higher-lift result with 30 Vol or 40 Vol, every service should be tailored to the individual client.
With OSMO IKON professional colour and developers, colourists can build formulas around the client’s hair needs, desired finish and long-term colour journey. Always follow the relevant technical guidance and product instructions to achieve the best possible result.