This is a highly specialised service, by quotation only, as it involves a variety of different products, skills, and knowledge to perform. Testing is required before a colour correction service can take place in order to:
check the health and condition of the scalp;
assess the strength and viability of hair to be treated;
establish how easily colour change might occur;
test for the presence of metallic salts (sometimes used in box-dyes) as these are incompatible with salon products.
Successful removal and re-colouring can be extremely complex and - even after several tests - it's impossible to accurately predict finished results. This is especially true when home dyes have been used more than once because they contain maximum-strength ingredients to ensure they work on every hair type and because they result in colour 'build-up' after repeated applications.
Hair under the microscope
What looks like a simple strand of silk to the human eye is actually something much more complex inside - and far more delicate too:
Each time a colour service is performed, the protective outer cuticle has to be opened up - rather like lifting roof tiles - so that tiny pigments of colour can be slotted inside. Then they need to be closed back down again to lock the colour in. Unfortunately, cuticles never re-close completely, which means repeated colouring can cause progressive roughness and lead to hair that snags easily and eventually splits and snaps.
Knowledgeable and skilled colourists have a huge array of colours, toners and varying-strength developers at their disposal. Tints and tones applied in-salon are mixed and blended precisely - unlike colour box-dyes which can’t take account of colours naturally present in the hair and simply provide blanket coverage strong enough to cover all hair. Unlike box-dyes, colourists use the lowest developer strength possible to deliver colour into the hair shaft with minimal damage, and they don’t cover the same sections over and over again unless they're ready for re-colouring. This minimises colour build-up and prevents unnecessary damage.
Changing or lifting colour is an even more complicated business because it involves breaking down unwanted pigments within the hair shaft (red disperses the slowest and is hardest to remove) in order for new colour to take its place. Some areas lift at different rates and can produce a patchy appearance. This is because porosity differs in some places from previous treatments. Patchiness needs to be monitored closely.
Bleach is the most effective solution for removing colour but, unfortunately, it is also the most destructive and should only be used with extreme caution. Shop bought 'colour strippers' are likely to be pure bleach and should not be used at home. Salons prefer a less aggressive approach and start with professional products (such as L’Oreal Effassor) opting for bleach as a last resort. Don't misunderstand - bleach is still widely used in salons but is monitored very closely during development. Hair that isn't strong enough simply won't be treated.
When colour correction involves high-lifts such as platinum blondes, toners are almost always required to counteract stubborn gold and red tones and colourists are trained in balancing out opposite tones.
Sometimes it is impossible, even for the most experienced colourist, to achieve the desired outcome in one session and on these occasions we would recommend a course of Pro-Fiber Hair Repair treatments before the further attempts were undertaken.