It is possible to determine whether it is permissible in Islam for a person whose hair is fair or has grayed as follows:
Before the advent of Islam, Jews and Christians avoided dyeing and changing the color of the hair thinking that seeming beautiful and adorning oneself did not comply with worshipping Allah.
Hazrat Prophet told his Companions that they could dye their hair and beard with henna or other dyes to make them earn independent personalities. The following is stated in a hadith reported by Abu Hurayra (may Allah be pleased with him):
"Jews and Christians do not dye their hair: Do the opposite of what they do; that is, dye your hair " (Bukhari, Anbiya, 50; Libas, 67; Muslim, Libas, 80; Abu Dawud, Tarajjul, 18; Nasai, Zinah, 14).
However, the order in the hadith is not binding; it is recommendation. As a matter of fact, some Companions like Hazrat Abu Bakr, Umar, Ali, Ka'b and Anas (may Allah be pleased with them) did not dye their hair.
On the other hand, the color black should not be preferred to dye the hair because black dye is in question for old men whose hair grays. Black color makes an old man seem younger. This case may change the purpose of dyeing in the wrong way.
As a matter of fact, when the Messenger of Allah (pbuh) saw that the hair of Abu Quhafa, the old father of Hazrat Abu Bakr, was fully gray on the day of the conquest of Makkah, he said,
"Change this gray hair and avoid black." (see Abu Dawud, Tarajjul, 18; Nasai, Zinah, 15; Ahmed b. Hanbal, I,165, 356, II, 261, 499, III,160, 322).
However, if the person whose hair is gray is a young person, there is no drawback to him dyeing it black. As a matter of fact, it is reported that Companions like Sa'd b. Abi Waqqas, Uqba b. Amrr, Hasan, Husayn and Jarir preferred this color. (Yusuf al-Qardawi, al-Halal wal-Haram fil-Islam, Trns by Mustafa Varlı, Ankara 1970, p. 102, 103)
The Messenger of Allah recommended henna as dye: "The best thing to be used to change the color of the gray hair is henna and flax." (Abu Dawud, Tarajjul, 18; Tirmidhi, Libas, 20; Nasai, Zinah, 16; Ibn Majah, Libas, 32; Ahmed b. Hanbal, V, 147, 150, 154). Hazrat Anas b. Malik reported that Hazrat Abu Bakr dyed his hair with henna and flax and that Hazrat Umar dyed with pure henna. (al-Qardawi, ibid, p. 103).
In conclusion, it is regarded mustahab (recommended) for men and women to dye their graying hair yellow or red but it is not regarded permissible to dye them black according to the sound view. However, there is no drawback to a young person to dye his hair black. On the other hand, henna and wasima (a plant used in paint industry) are recommended to be used as dye. (Ibn Abidin, Raddul-Mukhtar, Trns by Ahmed Davudoğlu, Istanbul 1982-1988, XV, 378, XVII, 314)
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