Working from his Paris home, Schueller adapted the principles and chemical ingredients utilised  in the production of fabric dyes for use on human hair.  Schueller’s first efforts resulted in a limited range of dark, golden and red shades on natural bases, but the effect on the hair industry was revolutionary.  This small home pharmacy became the centre of authority on hair cosmetics. From Schueller’s work, the entire hair dye industry was born.  Eugene Schueller called his permanent hair colour manufacturing company L’Oreal.

Using chemicals which delivered colour pigmentation identical to  human hair, Eugene Schueller and other pioneering cosmetic experts were able to duplicate the primary molecules, creating large black and brown and smaller red and yellow pigments.   Further experiments  revealed that the chemicals, when mixed with peroxide and ammonia become permanently locked into the hair shaft.  The chemicals were called ‘oxidation dyes’ because their reaction to oxygen (via the peroxide) is vital to the ability to permanently alter hair colour.  Oxidation dyes became the first fully permanent method of dying hair. Previously ‘Direct Dyes’ (such as plants and industrial chemicals used to colour fabrics) offered only a temporary colour alteration

How Permanent Hair Colours Work

Based on the principle that peroxide enters the hair and tries to attach itself to molecules in order to revert to water, it was discovered that when low strength peroxide is mixed with colour molecule chemicals the solution enters the hair, but once inside the cortex the peroxide not only tries to attach to the hairs natural pigment but also the artificial pigment.  These artificial pigments swell and link to one another (due to the peroxide attaching and creating a link between them) and become trapped inside the hair – permanently

Translucent hair

Perhaps the biggest conundrum facing chemists when producing an effective hair colour range was attempting to duplicate the shades found naturally in all hair types.  Human hair consists of four colour pigments; black, brown, red and yellow.  The size of pigments molecules vary (black being the largest and yellow the smallest) and each is present to varying degrees in every human head of hair.  When light shines through the semi-transparent cuticle layer, the hair colour is projected.  The combination of thousands of hairs all varying in colour, give an appearance of depth and shade that leads us to distinguish one particular overall hair colour.  It’s very much like looking at sand; there are hundreds of differing white and brown grains on a beach, but the ratio of the colours determines whether we see a tropical white shoreline or volcanic black beaches.  Our eyes can only see one predominant colour, only very close inspection exposes detail.

The Universal Hair Colour Numbering System

Cosmetic companies had successfully accomplished the task of creating a method of permanently lightening and darkening the hair, in addition to producing the key pigment molecules of black, brown, red and yellow.  However, in order to successfully duplicate the hundreds upon hundreds of natural hair colours, a formula had to be established that allowed control over the levels of tone found in the hair.  Whilst natural pigment filters through the cuticle layer to create varying blondes, reds and brunettes – artificial colours tended to make the hair look merely yellow, red, brown or black.    Working with the universal colour principles, scientists introduced three colours into permanent hair dye formula ingredients which are not found within the human hair pigment range (unless you are a cast member on The Simpsons of course!).  These colours were blue, green and violet.  With the valuable primary colour of blue and the equally important secondary colours of green and violet, experts had a palette with which they could create a boundless range of colour shades.  Scientists developed the 16 hair colorants, from which every possible shade can be achieved.  They gave these shades a numbering system, which is still used today and informs the technical language which competent hairstylists and industry professionals specify hair colours.  It is called the Universal Number System and is separated into depth and tone as shown in these tables

Depth (Base)

1.0    Black

2.0    Darkest Brown

3.0    Dark Brown

4.0    Medium Brown

5.0    Light Brown

6.0    Dark Blonde

7.0    Medium Blonde

8.0    Light Blonde

9.0    Very Light Blonde

10.0    Lightest Blonde/Pale

We then have the six tones that can be added to any of these above colours to create every hair shade you may wish to achieve:-

Tone

1.    Blue

2.    Green (referred to as Ash)

3.    Violet

4.    Red

5.    Orange

6.    Yellow

When you study any hair colour chart or permanent hair colorant product, every shade you see has been formulated from a mixture of these above colours.  It is the levels of depth (or base colour as it professionally called) against tone.  

When  hair is darkened by a permanent colour, the base ingredient within the chosen shade will transform every hair to the same depth, so overall results will appear much darker than expected.  For this reason, when deciding upon a preferable colour to use, always choose one shade lighter than you see your hair.  All good hairstylists will understand this without question and simply select a shade above the one you select.  However occasionally this is not the case.  I recall the distress of a client I once worked with, who had requested a young ‘trendy salon’ stylist to transform her mousy blonde hair into the rich brunette tresses sported by Catherine Zeta Jones.  Obviously not applying the ‘one shade below’ principle, the stylist left this distraught client baring more resemblance to Morticia Adams than Mrs Michael Douglas!   So stick with the ‘base rules’, when darkening with permanent colour.  

Colouring Hair is simple

After reading all of this you will probably be thinking that mixing and developing hair colour products is a complicated and technical task.  In fact it is exceptionally easy.  Many home application products come with an applicator bottle into which you add the developer to the colourant and mix prior to applying. The disadvantage of this  method is that it requires the user to mix all the product each time, even though there is only a need to colour the re-growth (roots). This in turn encourages the user to apply all the product each time and as mentioned below, putting colour onto already coloured hair can lead to build up of dye in the hair and the consequent darkening and damage to the hair  Some DIY hair colour products come with colourant and the developer in separate bottles allowing you to mix the amount required for the job in hand, and so long as  the two parts have not been mixed the product can be saved for the next application.  Leaving the mixed  tint to stand for any length of time before application  is out of the question. Remember, once peroxide is exposed to oxygen it will begin to oxidize and lose it’s colouring ability. Remember not to apply hair colour to wet hair, this will dilute the product and cause it to run down your face

Development time for tint (once applied to the hair) is also very simply.  In general, tint develops over 40 to 45 minutes.    Once the development time has been reached it will not continue to work and is relatively safe to be left on the hair, without fear of damage or destruction. After the development time, simply rinse from the hair and shampoo. It is important that you choose a shampoo that will not strip the colour from your hair, look for a low PH shampoo as this will not force the hair cuticle open and release the colour.

There is a terrible habit for people to keep putting colour on over coloured hair, by applying more and more permanent colour to the hair in the hope of achieving a dramatic change. You are likely to find yourself in a situation where very dramatic treatment will be required to remedy the damage to your hair.    Rather than lightening, the hair keeps accepting the new pigment (turning darker with each application).  In the end the cortex is packed so tightly with pigment build up, that it is unable to accept anymore colour molecules and the hair will assume a dull, almost black colour.  In these cases, a standard colour remover will not have the strength to dissolve sufficient pigment, instead bleach and 40  (sometimes 60) volume peroxide has to be used.  Continually smothering the entire length of hair in permanent tint every six to eight weeks creates unbelievable pigment build up on hair longer than shoulder length.  In fact I have seen cases of people who have been using a dark blonde to cover grey actually sport a dull dark brown shade at mid lengths and ends, following 18 months hair growth and 12 overlapping applications of tint during this timeframe.  In short, when your roots require attention, make sure it’s only these areas receiving it.

Allergic Reaction To Hair Colour

When using permanent tints, there is always the threat of allergic reaction looming over our heads.  In general, most people are not allergic to tint, however some are.

    It is important to distinguish between ‘allergy’ and ‘aggravation’ when tint is applied to the hair.   Numerous is the client whose hair to which I have been routinely applying tint, to state during the application “I think I’m allergic to this, it’s stinging and itching my head”.  It is highly probable on all of us, that the encounter between skin and permanent tint will cause some discomfort.  In general, this discomfort tends to increase the stronger the peroxide used becomes.  Remember that most tints also contain Ammonia which causes aggravation,  so combine this with peroxide and the effects can be harsh.  I find those who generally find discomfort with tint have sensitive skin anyway.  In my experience, aggravation tends to begin at application with anything from a subtle tingling sensation to a definite burning; however after a few minutes it tends to subside.  If the tint is really causing distress, after 15 minutes (or less) it should be removed with cool water.  Rinsing for at least 10 minutes and applying Aloe Vera will also soothe any burning sensation.  In these circumstances your skin is far too sensitive to tolerate permanent tints on the scalp.  In future use a non Ammonia product or a  different application methods; such as foils and cap which keep the chemicals out of contact from the skin.

Whilst the above demonstrates the affects of reaction to sensitive skin, this is not to be confused with allergy.  

Allergic reactions to tint are far more severe than mild skin aggravation, and symptoms usually manifest up to 48 hours after application.  When someone has an allergic reaction to tint, it is due to a high intolerance to the active chemicals used in the pigments in colouring products.  The chemicals that are  mainly responsible for allergic reaction are know as ‘Para Dyes’, Phenyldiamines or PPds.  Typical allergic reaction causes the face to swell sometimes to alarming proportions, the eyes closing and in some (very severe cases) the lips and throat beginning to swell and restrict.  There are more mild reactions that include: the scalp developing a nasty rash or welts and severe irritation, which leads to the skin weeping sometimes a sufferer will also develop headaches.

    When symptoms of an allergic reaction to permanent colourant appear, medical assistance should be immediately sought, It. is often necessary to administer anti-histamine or even steroids and adrenalin to relieve the discomfort.  

  As you can see, genuine allergic reaction is a totally different kettle of fish to standard tint aggravation.  Whilst a certain degree of skin unsettlement is expected (albeit very mild), severe aggravation and most importantly -allergy - is not.  This is perhaps one of the most dangerous potential side effects of using permanent colour.

 For this reason, prior to any tint application it is very important to do a skin test before every application, because an allergic reaction may occur even though you may have coloured your hair for many years without any problem

A skin test is quick and simple to carry out.  A small amount of tint and developer (the size of a pea) are mixed and dabbed behind the ear or elbow using cotton wool.   Ensure you immediately seal the bottles after pouring your pea sized measures.  The test  should remain 48 hours, initially it is common to feel tingling or slight irritation from the tint and the skin may redden subtly.  However, these sensations should disappear within a maximum of 60 minutes.  If, once applied the test causes severe burning, itching and or begins to inflame rinse the skin immediately with cool water.  In addition, if the skin is still reacting after several hours and appears patchy, a reaction has happened.  People may initially find the skin shows no response to the tint.  However 12 hours after initial application it may suddenly become inflamed and swollen.      In this case you are very likely to be allergic to tint, and a scalp application must not be carried out

Temporary Colours

Temporary colours are exactly as they claim to be, temporary.  They have no ability to remain in the hair any longer than until the next wash flushes all traces of their paint like effects confidently down the plug hole.  

    The molecules found within temporary colour are much larger than those seen in permanent (or even semi-permanent) colorants.  They also contain no peroxide or ammonia.  Unlike permanent tints which penetrate and swell deep inside the hair, temporaries simply sit on the outside of the hair shaft akin more to paint than a hair dye.  In fact they derive from ingredients which are used for standard (non hair) dyes.  Because there are no fervent chemicals used within temporary colour, they have zero ability to change (or even damage) the hair in any way shape or form.  They are manufactured as a one element product, meaning that two elements do not need to be mixed together in order for the product to activate and become effective.  Most common forms of temporary colour are sold as mousses, gels,

sprays and setting lotions (if you have ever spotted an infamous ‘blue rinse’ on a distinctive older lady, you will understand the method behind this application).  In addition temporary colour can be purchased as a simple liquid which the hair is doused in after washing.  In general most temporaries are applied to the hair when wet, prior to drying and styling.  However those which have very strong styling capabilities such as sprays and gels tend to be applied when the hair is dry and finished.  These particular colours tend to be brighter and designed for more ostentatious results.  

    In general the colour results achieved with temporary colours are fairly weak.  On very light hair you may successfully obtain a brand new base colour and tone, if you build up several layers of differing colours.  However in most cases a temporary colour can simply offer a subtle shade change, or if using sprays and gels (which are heavy and very ‘paint like’) maybe a garish primary colour could be achieved that sets off a formidable Mohican perfectly.  Tones achieved with temporary colours work well if trying to rid the hair of yellow traces (applying a platinum or violet mousse after washing keeps bleached and very white hair looking clean and chic).  In addition, hair with only minimal grey can be partially converted back to its original colour with the application of a good temporary.