[Sauerkraut]

Again way over my head. I am amazed anything I write even works. Anyhow using PostUpdate works and seems to be doing exactly what I needed.

local PostUpdatePower = function(Power, unit, min, max)
	local _, ptype = UnitPowerType("player")
        if(oUF.colors.power[ptype]) then
		r, g, b = unpack(oUF.colors.power[ptype])
	end
	Power.arrow:SetVertexColor(r, g, b)
end

		s.PostUpdate = PostUpdatePower

It may not be the most elegant or the best way to do it, but it seems to work.