On this issue the best I could do is to cite here one of my earlier answers:

“There is no disagreement among scholars about the permissibility of dying the hair with other than black color such as yellow or red. For all consider it as either permissible or recommended.

As for dying with black, scholars have been clearly divided on this issue while agreeing on two points: 1. It is permissible in jihad; 2. It is wholly impermissible in order to cheat people about his or her real age as is the case in proposing for marriage.

Dying with black color in all other situations is contentious.

1- One group of scholars considers it undesirable. This is the position of Maliki and Hanbali schools; it is also one of the options in both the Hanafi and Shafi schools as well.

2- A second group considers it as haraam; this is one of the views in the Shafi schools; it has been authenticated by Imam Nawawi and a number of other scholars.

3- There is a third view held by a minority of scholars who considers it as permissible. This is one of the views in the Hanafi school as mentioned by Ibn Abideen; it has been attributed to Imam Abu Yusuf.

4- There is a forth group that made a distinction between man and woman; thus they allowed it in case of women, while disallowed it in the case of men.

Perhaps the view that is closer to the evidence is to say it is undesirable, and it is best to avoid it. In other words, one incurs no sin, if he or she were to do it–unless they are using it to deceive people about their real age.

The differences among scholars on this issue are because of the conflicting reports on this issue in the sources. There are reports that allow use of black colour in case of war and clear texts prohibiting it if it were done with the deliberate intention of deceiving people of one’s true age where one needs to disclose it.  So there is a virtual consensus on the above two points.

While we move away from these cases, we are faced with conflicting evidence. The issue is complicated further when we see reports of a number of companions dying their hair with black in situations different from the above. Those who either permit it or do not declare is as haraam are relying on them. For it is unlikely that the companions would resort to it, if it had been forbidden.

The names of those who dyed their hair black included a number of companions, successors and others. The list of the companions who dyed their hair black include Hasan and Husain, the Prophet’s grandchildren,  Uthman b. Affan, the  third caliph, Sa’ad b. Abi Waqqas, Abd Allah b. Ja’far, Uqbah b. Aamir, Mughirah b. Shu’bah, Jarir b. Abd Allah. And the successors included Ali b. Abd Allah b. Abbas, Abu Salamah b. Abd al-Rahman, al-Zuhri and others. Scholars who practiced it in the later generations included Ibn Jurayj, Abu Yusuf, Ibn Abi Layla, Nafi b. Jubayr, Qasim b. Sallam, etc., etc.”

Almighty Allah knows best.