How valid is the statement that it is permissible for a young man, a mujahid, and the Imam of the Muslims to dye their hair?

The preponderant view among scholars is that dyeing hair black is absolutely forbidden, with the exception of the mujahid in war, in order to show youthfulness and strength to the disbelievers. As for dyeing hair with colors other than black, it is permissible for both men and women, as long as there is no harm. There is no evidence to suggest that the leader of the Muslims or young people are exempt from these rulings.