A study in color. (Termagants Gun Color)

I am trying to decide what color to paint the bio weapons on my Termagants, so I painted up some options, tonight, to see what I liked best.  If you have an opinion pleas chime in.

So this is the paint scheme for the army, the orange has not been added to any of the other models presented here.









 Here are the four options I have painted up, after the wash I know which I think stands out the best, but I like to know what you think.  Remember, there will be an orange added on top of the arms and legs.  I want to let the wash dry and go to bed, so I get to it tomorrow.
 

On a side note, after I get back from vacation in August, I putting this army on the shelf and getting my marries back out.  It will be nice to get back to an army were unit size is ten not twenty plus, at least painting wise.