I've seen some red here (at one of my local Coop locations) later in the spring / early summer, they also happened to have some blue potatoes at the time. I used the opportunity to make Red White and Blue potato salad for July 4th.
I've also picked up some baby red and white at Geant Casino (not sure of spelling) in France which I used simply quartered for my "Sunday Roast", they were really nice. Unfortunately, not so convenient to get to France from Zürich, just for potatoes.