None of the new laws affected open carry. There is a ban on transfer or purchase of >15 round magazines (and new shotgun restrictions) and a ban on private sales without a background check.
Open Carry is legal almost everywhere. The BIG exception is the actual City of Denver.
It's not customary though; it's rather unusual to see someone actually doing it. It's probably more common in Colorado Springs than elsewhere in the big cities; I've been spotting someone at least once a month of late.