Q. Is highlighting of Hair Allowed ?
A. In the name Of Allah the Most Merciful
Highlighting of the hair is allowed only if the following points are first taken into consideration first:
1. That it is done solely for the pleasure of the husband and not for fashion. If a married lady does it out of habit then this is permissible as long as it is her husband who gazes upon it. It is advisable that before an unmarried girl does this she looks at her intention.
2. The substance that you use on your hair is not alcoholic. Many hair dies contain Hydrogen peroxide (H202), which is non alcoholic and works by changing the hair pigment called melanin. Therefore, because the hair surface it not affected or coated (which would mean that the water will reach the hair strand) it would be permissible to use.
3. That your hair is not seen by a stranger, i.e. you wear a Hijaab (Scarf) if you go outside.
4. The substance which you use does not ?coat? the surface of the hair which would make it impermeable for water to reach the actual hair. Many hair dying agents work by coating the hair stand, which results in the water not reaching the hair. thus the Wudhu/Ghusl (bath) will not be valid.
5. Hair bleaches chemically alter the melanin granule in the middle layer of each hair strand, and this can prove very harmful for many individuals. When using harmful products on the body (without a valid reason or medical advice) it would be Makruh (Disliked) to do so. In my personal humble opinion Henna (Mendi) is probably the best substance to use and the closest to the Sunnah.
6. Many hair dyes come in temporary form, which eventually washes out, and others tend to be semi-permanent or permanent forms. The latter two can be harmful for your body. Again this would be Makruh
7. It should also be known that many hair dyes can result in hair loss and it is also a known fact that some hair colour dyes have been linked to different cancers (http://www.nontoxic-haircare.com). Again this would be Makruh.
In conclusion after having taken all of the above mentioned points into account I would say that is it better to not highlight the hair out of mere Fashion but for the happiness of the spouse.
Fatawa Rahimiyah Vol 7 Pg, Vol 8 Pg 93
Organic Chemistry, McMurry
Chemistry for the Pharmacy and life sciences, Gareth Thomas.
And Allah the All-Powerful knows best. --------------------------------------
Mufti Abubakr Karolia
Source : http://www.muftisays.com/qa/question/648/highlighting-of-hair.html