Dying the hair or the beard black

According to a Hadith found in Abu Dawud which is reported by Hazrat Abdullah Bin Abbaas (Radiyallahu Anhu), Rasulullah (Sallallaahu Alaihi Wasallam) said that in the last era, there will be people who will dye (their hair and beard) with black colour just like the stomach of pigeon. They are those who will not get the scent of Jannah. According to another Hadith found in Saheeh Muslim, Rasulullah (Sallallaahu Alaihi Wasallam) commanded to refrain from black colour. Thus, in the light of these Hadith, it is a very grave sin to dye the hair or beard black. If the hair or beard of a person became white, it is permissible to dye it with henna or a plant called Katam.

[English version of "Teine cheveu ou la barbe noir" – Al Jamiat – Vol.3 No.13]