On the day of the Conquest of Makkah, the Messenger of Allah (may Allah's peace and blessings be upon him) entered while wearing a black turban

The Hadīth reported by Jābir (may Allah be pleased with him) states that the Prophet (may Allah's peace and blessings be upon him) entered Makkah on the day of its conquest wearing a black turban. This indicates that it is permissible to wear black clothing. The second narration reporting that the Prophet gave a sermon while wearing a black turban shows the permissibility of wearing black clothes when delivering a sermon.

However, wearing white clothing is better as reported in a Sahīh Hadīth: "The best of your clothing is the white ones." Wearing black clothes by sermon givers is permissible, but white is better. That is the Prophet's wearing a black turban in this Hadīth just shows that it is permissible.

As for the other Hadīth reported by ‘Amr ibn Hurayth, saying: "I saw the Messenger of Allah (may Allah's peace and blessings be upon him) wearing a black turban with its ends hanging loose between his shoulders," it indicates the permissibility of wearing a black turban and letting its ends hang down between the shoulders.