Brown Orcs-uncorrupted orcs
Green Orcs-uncorrupted, but different skin color, because of fel magic
Red Orcs-orcs who have drank demon blood twice (Our timeline Shattered Hand Clan, Bleeding Hollow Clan and Bonechewer Clan)
White/Gray Orcs-uncorrupted orcs who have lived underground (Shattered Hand Clan)
Black/Dark Gray Orcs-uncorrupted orcs who have lived in mountains (Blackrock Clan and Dragonmaw Clan)