In the first place, it is to be noted that there is nothing specific in the Sunnah regarding the wearing of a turban. Wearing a turban is by large a habit that is determined according to the traditions of each specific society. There is nothing specific about its length, color, or shape.
To explain this concept, here are words of the prominent Muslim scholar Sheikh `Atiyyah Saqr, former Head of Al-Azhar Fatwa Committee: “Wearing a turban is an issue left to customs and traditions more than religion. Arabs used to wear turbans to save them from the heat of the sun, and so did the Prophet (peace and blessings be upon him). As for the narrations that make wearing a turban a part of the Sunnah, most such narrations cannot be taken as clear evidence because they are weak. According to Ibn Al-Haj, wearing a turban is one of the permissible acts, not a sunnah, because there is nothing clear that say it is a sunnah. Even when the Prophet put it on, he was not doing so as an act of worship; rather, it was a custom. There is a controversy regarding whether we should follow his example in this regard or not. He is reported to have worn headgears other than a turban. There is no specific colour for the turban. Upon entering Makkah, the Prophet (peace and blessings be upon him) was wearing a black turban. In the book of Zaad Al-Ma`aad, Muslim reported on the authority of `Amr ibn Huraith that he saw the Prophet (peace and blessings be upon him) on the pulpit wearing a black turban. Jabir ibn `Abdullah also reported that when entering Makkah, the Prophet (peace and blessings be upon him) was having a black turban.”