What is the ruling on dyeing a white beard?

Changing gray hair is a Sunnah with reddish-brown or yellow dye, and it is forbidden with black dye according to the sound opinion, except for the mujahid (fighter in the path of Allah). The Prophet, peace and blessings be upon him, commanded changing the gray hair of Abu Quhafah and avoiding black dye. The Prophet, peace and blessings be upon him, used to dye his hair with yellow, and he used henna and katam which is mixed with henna to give a reddish hue. Dyeing hair with pure black for someone other than a mujahid is not permissible religiously and may lead to deceiving a suitor.