The Rainbow Barbarians are Elves of Harnic origin. Over the last decades the Emperor and Arch Duke Eltán have made an effort to bring them culturally closer into the The Free Imperia by dispatching clerics and rangers to live with them, and having the tribes foster new spellcasters for apprenticeships to help in the rapid training and toughening of different corps through the Spellcaster Recruitment and Training Initiative. The Emperor remains Great Chieftan of the Rainbow Barbarians, and has set Eltán to be their Imperial Liason and nominal Military Commander, as Protector of the Harnic Elves. Eltán is smart enough to build respect instead of pushing them.
They are governed by the Council of Clan Chieftains under Great Chieftain Aragithalas Sercenornorow Kanan
Purple Pine Mountain Barbarians
The Rainbow Barbarians like to tell tales, and they don't necessarily read maps well, but they claim to have gone on walkabout, and to potentially have some tribe members on the ground somewhere in these areas: Barbarian Map Scribbles