If you decide that you want to completely change your colour, your hair will probably need to be pre-lightened. Hair dyes work by penetrating one or more of the three layers of the hair shaft, and are categorised according to how many layers they effect.
Temporary colours are useful for toning-down over-lightened hair, bringing out natural highlights, restoring faded colour to a natural shade, and adding colour without changing the condition. But their temporary nature means that they must be applied frequently to maintain desired effect, and as their consistency is very thin, it may not cover evenly.
Semi-permanent colours have smaller molecules, which means they are able to penetrate deeper into the middle layer of the hair shaft, to give a stronger colour that will last for up to six weeks. The colour fades gradually with washing, so there is no re-growth, and the built-in conditioners impart a healthy shine on the hair.
Semi permanents can also be used to cover grey, but generally application is advised only if the grey covers less than forty per cent of the head. Likewise, if the hair is pre-lightened the tint might not be absorbed evenly, and this will cause the hair to look patchy.
Like temporary colours, semi permanent dyes need to be re-applied every five weeks or so if the colour is to be maintained. They also have a very subtle effect on darker shades of hair, so if a stronger colour is required pre-lightening might be necessary.
If you want rich, bright, long-lasting colour, or you’re covering lots of greys, permanent colours are the answer. Because they are composed of very small molecules, permanents are able to penetrate deep into the cortex of the hair shaft.
Permanents give the most vibrant results; they can also lead to dryer, dull-looking hair. They require constant re-touching at the roots to disguise re-growth, and this can cause severe damage to the hair shaft, especially where the hair requires pre-lightening.
One of the oldest and safest methods of colouring hair is henna. Henna is a vegetable dye, derived from the henna bush, which grows in the Middle East, India and Africa. Although it can be regarded as a temporary dye, it penetrates the cortex of the hair shaft and, with repeated use, can have a permanent effect. Henna has three distinctive shades, black (derived from the root of the plant), red (from the leaves), and natural (from the stem).
Since it’s a natural product, there is no risk of damage to the hair shaft, and it will enhance both colour and shine. It also stains easily, so watch out for drips and splashes. Unfortunately modern-day henna treatments are sometimes mixed with other compounds and this can mean future chemical applications will not work effectively.
Always consider your skin tone when choosing a hair colour. Most hair colours suit everyone, including blonde against dark skin- more often it’s question of shade rather than the actual colour.
Another factor to consider is your age – some colours looks good against younger looking skin, yet unflattering to older complexions. Think about the colours of your clothes and makeup too, and be realistic about your hair type (is it prone to breakage?), the overall result you want to achieve, and whether you are prepared to maintain the colour. Remember also that some colours fade quicker than others, red for instance.
Dos and don’ts of hair colouring
Do go to a hair salon to have your hair coloured. Home colouring is fine if you’re staying the same shade, or if you want to cover grey (forty percent or less), as professional colour will look better and last longer.
Do consult your hairdresser if you have never coloured before, no matter what you’re planning.
Do consider your age and style – choose shades that flatter and complement your skin tone.
Do carry out a patch test before dying your hair. Trichologists sometimes see patients suffering allergic reactions to hair dyes, and if severe can cause contact dermatitis and permanent damage to the surface of the skin.
Don’t relax and tint hair in the same period. You should wait at least one to two weeks before each application. Follow your hairdresser’s advice.
Don’t mix colours. Some colours do not mix well and you could end up with a shade of green that you hadn’t planned on.
Don’t use henna if you have chemically treated hair. Ask your hairdresser for advice.
Always inform your hairdresser of all chemical applications.
Contact The Hair and Scalp Clinic for appointments on 0208 201 5555/07780 971239 or email firstname.lastname@example.org
About Shirley McDonald MIT – Consultant Trichologist
Since qualifying in 1991, Consultant Trichologist Shirley McDonald has studied advanced nutrition for practitioners with the Institute of Nutrition I.O.N and Natural Nutrition with the College of Natural Nutrition. Shirley has been a freelance writer for BH Magazine (Black Hair). Her features include braiding, chemical applications and dry scalp conditions. She has lectured at various hair events, including Alopecia UK 2015 . She has also been interviewed extensively both in print and broadcast media, appearing on shows like Radio 4’s Celebration of Women programme, BEN TV, Colour Radio and featured in Pride magazine.