top of page

Oxidative Dyes


1. relating to the process or result of oxidizing or being exposed to oxygen.


1. a dye, pigment, or other substance that colors something.

Oxidative Colorants are dyes used in both permanent and demi-permanent haircoloring products.

When these dyes are exposed to oxygen from developers/activators, they undergo a chemical reaction and change from being a colorless molecule into a completed colored dye molecule inside the cortex of the hair.

There are two main classes of oxidative colorants:

  • Precursors (sometimes called primary intermediates)

  • Couplers (sometimes called modifiers)

The final haircolor is formed when a precursor (or multiple precursors) reacts with a coupler (or multiple couplers) in the presence of developer (hydrogen peroxide).

For example, a dark blonde shade of haircolor (6N/6.0) is not just one “dye-molecule”, but tends to be a combination of precursors and couplers (these combinations are different from brand to brand.

Brand A’s 6N may have 2 precursors and 2 couplers in its formulation. Conversely Brand B’s 6N may be comprised of 3 precursors and 4 couplers in its formulation.

This explains why different brands not only look different, but can fade differently too.

Each manufacturer copyrights their shades, so each company has their own unique version of brown, blonde red etc.

There are only around a total 40 precursors and couplers that are used in all oxidative haircoloring products!

If you look at the visual below you can see that different precursors mixed with different couplers create a myriad of haircolor results:

The process of haircolor development is dependent on proper developer selection as well as timing.

Remember, higher volumes of developer can actually degrade the precursors and couplers in a permanent haircolor shade.

This is why 20 Volume is typically considered the standard developer choice when dealing with permanent haircolor shades in levels 1-10.

This is also why respecting the manufacturers recommended development time is KEY so that you give these precursors and couplers time to develop and fully form into a completed dye molecule in the hair.

Think of taking a cake out of the oven before it’s fully done. It may look great on the outside, but when you cut into that cake, it it’s an entirely different story.

If you don’t allow time for what haircolor chemists refer to as “maximum dye development” you run the risk of: 1) not getting the intended shade selected and 2) the longevity (staying power) of the shade could be compromised as its not fully "developed".

Remember the first permanent haircolor formulation was invented in 1908. It had an alkalizer, precursors, couplers and relied on hydrogen peroxide to develop the color into the final haircolor result. The same basic formulation framework is still used in the industry today.

So, not a lot has changed in 114 years. Like they say: “If it’s not broken, don’t fix it”!

Hope you found this information helpful! Next post we will talk alkalizers!



74 views0 comments

Recent Posts

See All

WHAT Is ME+. ??

ME+ dye technology, by Wella was created to minimize possible NEW allergy or sensitivity to hair color. It is present in many shades of Wella Kolestone Perfect Hair Color. This ingredient is a sci


Several manufacturers offer very effective, very low Ph shampoos intended for use ONLY at the backbar.. when lightener or color are being removed from the hair. These exist usually at a ph of around

‘COVERAGE’ of Gray.. Reality vs Perception

When gray hair is processed with a color formula ( category, level, tone, etc). The term ‘coverage’ is a matter of interpretation and perception. For many salon pros, ‘coverage’ of gray obtained from


bottom of page