Bet that contractor won't like taking it out and redoing it. But, it does look reddish.
Looks like we are going to be able to salvage the curbing. I took a pressure washer to it today and was able to remove the majority of the red. What's left is just a hint of it and looks brown now when wet. If it looks the same when we apply sealer it should turn out looking just fine. The underlying mortar is a tan in color and was able to bring most of that back out after pressure washing. I'll update pics after we seal it.