My bad. I read "plastic clips" and apparently glazed over the rest. I thought you were talking about the clips, not the actual trim that attaches to the clips. Mine are actual pieces of wood trim, not plastic. Are you trying to match some existing ones? Replacing existing ones?
You could always just purchase trim at a home store and cut it to size and paint it. I do not recall ever seeing those pieces made out of plastic, but apparently they do.