Nasai

(1) Thaghama is a plant that grows on the peak of a mountain. It bears white fruit and flowers. When it dries, its whiteness increases. And due to the abundance of flowers, even the tree appears white from a distance.

(2) "To abstain"—when an elderly person, from whom there is no risk of deception, is prohibited from using black dye, then how can it be permissible for someone in whom there is a possibility of deception?

(3) "Abu Quhafa" was the respected father of Abu Bakr as-Siddiq radi Allahu anhu.

Hadith Commentary: Benefits and Issues: Abu Quhafa, ‘Uthman bin ‘Amir al-Taymi radi Allahu anhu, was the respected father of Abu Bakr al-Siddiq radi Allahu anhu. He accepted Islam at the time of the conquest of Makkah. Thagham is a plant whose flowers are extremely white. This hadith proves that if the hair has become completely white, then it is better to dye it. As for those hadiths in which there is prohibition, that applies in the case when the hair is not completely white, or if it is dyed with black color, because dyeing with black color has been explicitly prohibited by the Prophet sallallahu alayhi wa sallam. As for the reports from some Companions and Followers (Tabi‘in) regarding the use of black dye, that was either mixed with henna (mehndi), or in the state of war. The fundamental matter is the Sunnah; in comparison to it, the action of any individual is not a proof.

Benefits and Issues:
It is impermissible to dye the hair of the head or the beard with black color.

Commentary:
Benefits and Issues:

➊
Abu Quhafa (radi Allahu anhu) was the respected father of Abu Bakr as-Siddiq (radi Allahu anhu).
His name was Uthman bin Amir (radi Allahu anhu).
He accepted Islam at the time of the conquest of Makkah.
He passed away during the caliphate of Umar (radi Allahu anhu) in the year 14 Hijri at the age of 97.

➋
One should avoid using pure black dye.

For details, see ahadith: 5086 to 5089.

Benefits and Issues:
In Nasai, Abu Dawood, and Ibn Majah, the wording is: "Keep it away with black color." Here, there is a command to avoid and abstain from «سواد». And a command (amr) is for obligation. Therefore, acting contrary to it is prohibited and unlawful.

«قال النووي فى شرح مسلم تحت الحديث : ويحرم خضابه بالسواد على الأصح. وقيل: يكره كراهة تنزيه، والمختار: التحريم لقوله صلى الله عليه وسلم: واجتنبوا السواد الخ وقال الحافظ ابن حجر في: فتح الباري ثم إن المأذون فيه مقيد بغير السواد لما أخرجه مسلم من حديث جابر أنه صلى الله عليه وسلم قال غيروه وجنبوه السواد۔ الخ وقال السندي فى حاشية ابن ماجه وفيه ان الحضاب بالسواد حرام او مكروه۔ وفي تحفة الاحوذي فقوله صلى الله عليه وسلم : واجتنبوا السواد دليل واضح على النهي عن الخضاب بالسواد»

That is, Imam Nawawi, in Sharh Muslim, under this hadith, states that the correct view is that dyeing with black color is haram (forbidden). Some have said it is disliked (karahat tanzihiyyah), but the preferred opinion is prohibition (tahrim), because the Messenger of Allah (sallallahu alayhi wa sallam) commanded to avoid it.

◈ And Hafiz Ibn Hajar rahimahullah says in Fath al-Bari that in this hadith of Jabir radi Allahu anhu there is evidence that permission is only for such dye that is not black in color.

◈ And Allamah Abu al-Hasan al-Sindi, in the marginal notes of Ibn Majah, says that in this hadith there is evidence that dyeing with black color is haram or at least disliked (makruh).

◈ Similarly, in Tuhfat al-Ahwadhi, the commentary of Jami' al-Tirmidhi, it is stated: The statement of the Messenger of Allah (sallallahu alayhi wa sallam) is clear evidence for the prohibition of dyeing with black color.