[Sylen]

I use this for highlighting debuffs

--Highlight Purgable Magic Buffs on Target and Focus 
hooksecurefunc("TargetFrame_UpdateAuras", function(s)
    for i = 1, MAX_TARGET_BUFFS do
        _, ic, _, dT = UnitBuff(s.unit, i)
        if(ic and (not s.maxBuffs or i<=s.maxBuffs)) then
            fS=_G[s:GetName().."Buff"..i.."Stealable"]
            if(UnitIsEnemy(PlayerFrame.unit, s.unit) and dT=="Magic") then
                fS:Show()
            else
                fS:Hide()
            end
        end
    end
end)

With some classes getting a dispel for enrage effects back, might want to use this

--Highlight Purgable Enrage Buffs on Target and Focus 
--Enrage effects return an empty string as debuffType
hooksecurefunc("TargetFrame_UpdateAuras", function(s)
    for i = 1, MAX_TARGET_BUFFS do
        _, ic, _, dT = UnitBuff(s.unit, i)
        if(ic and (not s.maxBuffs or i<=s.maxBuffs)) then
            fS=_G[s:GetName().."Buff"..i.."Stealable"]
            if(UnitIsEnemy(PlayerFrame.unit, s.unit) and dT=="") then
                fS:Show()
            else
                fS:Hide()
            end
        end
    end
end)