[lore_master]

the Istari, which were wizards sent form the west(Valinor)had different ranks, similar to that of officers in the millitary. there were 5 Istar, and 4 ranks:

pallando:blue
alastar:blue
radagast:brown
gandalf:grey
sauruman:white

the blue wizards went off to the east with sauruman and were never seen or heard from again, but sauruman returned, it is thought that the blue wizards started many different cults and religions in middle earth.

radagast was never realy interrested in people and hung aroung with birds and other animals. he probably never went back to the west.

gandalf was second in command of the order untill sauruman betrayed the west and was cast down form the order. when he died fighting with the balrog, his sprit went back to the west but was sent back because he had not finnished the Istari's mission, which was to give hope and strengh to those who had to combat sauron.

sauruman was the leader, but was cast away form the order wehn he betrayed them and alleid himself to sauron.
when he died his spirit was not allowed to return to the west but wander the void forever.

hope that answers your question