Dr. Muzammil H. Siddiqi, President of the Fiqh Council of North America, states:
“The wisdom behind prohibition of dying hair is that: It is an unnecessary pre-occupation. It may also be considered deception, if one is trying to hide one’s real age or identity.
However, it is permissible for men or women who are young and have a lot of gray hair to dye with black colour or with henna. old people who have very white hair can also dye them, unless their intention is to hide their real age or identity.“
Moreover, the prominent Muslim scholar and da`iyah based in London Zienab Mostafa, states the following: “Dyeing the hair is not considered changing the form that Allah created. The change forbidden to do is the permanent one such as changing the shape of the nose, teeth, eyebrows, etc.
as for dyeing hair, it is permissible. For young ladies dyeing hair with any color is not haram. As for old ladies they can dye their hair to change the grey, if they want, with any color except black in order to avoid any form of deceit for people who might think they seem younger.”