WoWInterface - Code works but not 100% yet

I was able to get the color code to work on the health text but it's changing color when clicking on a target or switching from yellow to green also. I was going to use the same code to change the color for the power text but I'm not any good at lua programming.

Code:

hooksecurefunc("TextStatusBar_UpdateTextStringWithValues",function(statusFrame, _, value, valueMin, valueMax)

 local statusFrame = PlayerFrameHealthBarText

 if statusFrame and PlayerFrameHealthBarTextLeft and PlayerFrameHealthBarTextRight then

 local percent = value / valueMax

 local r,g,b = 1,0.82,0 -- yellow

 if percent < 0.335 then

 r,g,b = 1,0,0 -- red

 elseif percent > 0.665 then

 r,g,b = 0,1,0 -- green

 end

 PlayerFrameHealthBarTextLeft:SetTextColor(r,g,b)

 PlayerFrameHealthBarTextRight:SetTextColor(r,g,b)

 end

end)