[Closed] change properties of Material Editor renderer

How can I change properties of Material Editor renderer?
I’ve tried (using vray here)

t = vray()
    t.colorMapping_brightMult = 10.0
   renderers.medit_locked = false
   renderers.medit = t

     But it does nothing, no difference at all. In the same time if I assign the same variable to [b]renderers.current[/b] it works fine.
     This does not work either (vray assign to medit renderer manually):

renderers.medit_locked = false
 renderers.medit.colorMapping_brightMult = 10.0

     off topic: good thing is that I could use different render settings in different render "instances" but that is not my point right now.