What is the ruling on a man dyeing his hair or beard black, knowing that some of the Companions used to do that?

Al-Shawkani mentioned that some scholars disliked dyeing grey hair black, and some prohibited it, noting the اختلاف (disagreement) among the Companions regarding this. The preponderant view is the prohibition of dyeing with black, due to the Prophet's (peace be upon him) statement concerning Abu Quhafah: "Change this, but avoid black," and due to his (peace be upon him) statement: "There will be people at the end of time who dye their hair black like the crops of pigeons; they will not smell the fragrance of Paradise." Al-Nawawi mentioned that the view of the Shafi'i school is the recommendation of dyeing grey hair with colors other than black, and its prohibition with black.