Update:
Have written to the supplier. There are "NO" distinction by the color of the bracket.
But there was a bad batch. Now we wait and see what makes the replacement.
If that works, the evaluation will be adjusted accordingly.
Thanks for the fast response of the supplier. (And the m Saturday)
For that I give it 5 stars.
Update: 04/24/2015
So the batch with the red iron is super.
Have increased to 5-star.