This is where I grew up - Canton Graubünden, Switzerland. The red trains belong to the canton railway RhB. Quite unmistakable. They are mostly, but not entirely integrated with the national railway service SBB/CFF.
Interestingly, RhB still use a track width that is narrower than the standard used by SBB and all the other major railways in Europe. It was chosen as adaptation to the alpine conditions that required lots of bridges and tunnels.
