[zork]

@Kraut
There are events to track the druid shapeshift.

Your arrow frame needs to hook them and change it's color accordingly.

The unit powertype colors of oUF are initiated on login.

By the time it loads it may be possible that UnitPowerType("player") still returns nil. But not sure about that. I think it should work, at least UnitClass etc. does.

EVENT: UNIT_DISPLAYPOWER "Fired when the unit's mana stype is changed. Occurs when a druid shapeshifts as well as in certain other cases." http://wowprogramming.com/docs/events/UNIT_DISPLAYPOWER

Basically...register the event to your arrow frame and then call UnitPowerType player and set the color of the arrow.

I recommend registering PLAYER_LOGIN aswell. By that time the function will be working and you should be able to set the color correctly.

Sth like this should work...

--set color
  lib.setArrowColor = function(self)
    local _, pType = UnitPowerType("player")
    local pcolor = oUF.colors.power[pType] or {.3,.45,.65}
    self.arrow:SetVertexColor(unpack(pcolor))
  end
  
  --hook events  
  self:RegisterEvent("PLAYER_LOGIN", lib.setArrowColor)
  self:RegisterEvent("PLAYER_ENTERING_WORLD", lib.setArrowColor)
  self:RegisterEvent("UNIT_DISPLAYPOWER", lib.setArrowColor)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Btw I found a neat trick for threat coloring (I guess I'm the last one to find out about forceUpdate O_O).
It is awesome because if color is set via self.Health.colorHealth = true then if you don't have aggro the color will stay and the color is updated as soon as any of the events if fired.

--update health func
  lib.updateHealth = function(bar, unit, min, max)
    --color the hp bar in red if the unit has aggro
    if unit and UnitThreatSituation(unit) == 3 then
      bar:SetStatusBarColor(1,0,0)
      if bar.bg then bar.bg:SetVertexColor(1*bar.bg.multiplier,0,0) end
    end   
  end
  
  --check threat
  lib.checkThreat = function(self,event,unit)
    --force an update on the health frame
    self.Health:ForceUpdate()
  end
 
  self.Health.PostUpdate = lib.updateHealth
  self:RegisterEvent("PLAYER_TARGET_CHANGED", lib.checkThreat)
  self:RegisterEvent("UNIT_THREAT_SITUATION_UPDATE", lib.checkThreat)