Under the Taliban some men wore black and some wore white turbans, Is there any significance to this
Although many Sikh men and women choose to don a White, Off-White or a similar shade daily as part of their beliefs in keeping with the faith. It is also a common color worn by Eastern Sikhs at events such as a funeral ceremony or any event where a bright color would not be considered appropriate. On the other hand, Western Sikhs commonly wear White as part of their daily Sikh garb. Black and Navy are more popular with the younger generation and also worn at more formal events such as black tie dinners and parties.
In Islamic cultures, not dissimilar to many Western cultures, white is considered to represent purity. Religious scholars thus assert it to be a suitable color for a pious man, especially while going to prayer on a Friday.
The black turban is more specific. It is traditionally only worn by "sayyids" or "sharifs" - men who are directly descended from the Prophet Mohammad via his daughter Fatima and her husband `Ali. It is a mark of honor in the Muslim world and a sayyid can expect a little extra respect due to his birth from other Muslims.
This is the answer I have found and copied for you.
I have seen this written and heard it on documentaries many times. So I'd say it's the real reason for the black and white headgear."The Black colour turban is worn by muslim clerics who are the direct descendants of the Prophet Mohammad (Peace be Unto him).
Whereas, the white colour turban is worn by muslim clerics who are not the direct descendants of the Great Prophet.
This trend is more prominent in the Shia clerics. I am not sure if it exists in the Sunni clerics also."
.................................................. .................................................. ...."Black Ammama (headress) signifies that the cleric is Saiyed(descendent of prophet Mohammad) and White Ammama is worn by non-saiyeds."
So we can tell the good (white hat) from the bad guys (black hat/turban).