What are the sunnah colors for the turban. I have heard the green turban, black, red, brown, yellowish is sunnah

Black

Jaabir ibn Abdullah [radhiallaahu anhu] narrates that Nabi [sallallaahu alayhi wasallam] entered on the day of Fath-Makkah whilst wearing a black Turban. (Muslim, Abu Dawud, Tirmidhi, Nasaaie, ibn Majah)

Yellow

Ibn Umar [radhiallaahu anhu] narrates that Nabi [sallallaahu alayhi wasallam] used to dye all his clothes with yellow, even his turban. (Sunan Abi Dawud)

Red

Anas ibn Maalik [radhiallaahu anhu] narrates seeing Nabi [sallallaahu alayhi wasallam] making Wudhu whilst wearing a Turban that had red colour on it. (Sunan Abi Dawud; Mustadrak al-Haakim)

White

Ibn Umar [radhiallaahu anhu] narrates Nabi [sallallaahu alayhi wasallam] tied a white turban for Abdur-Rahmaan ibn Awf [radhiallaahu anhu]. (Mustadrak al-Haakim)

Green

Nabi [sallallaahu alayhi wasallam] never wore a green turban. (Sha-aabeeba al-Ghamaama fiy Tahqeeq Mas-alah al-Imaamah pg.59; Basaair)

However, some Sahaaba [radhiallaahu anhum] have worn the green turban. (Musannaf ibn Abi Shaybah).

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai