Sheadewie17
On the Monte Bré English website, the term “Arcobaleno Pass” for that discount is indeed misleading. In the German version, they named it “Abonnement Arcobaleno”, which usually would refer to monthly or yearly subscription-type passes for residents.
But hey, simply get that ticket on site at the funicalury station, present them your arcobaleno day pass along with a friendly greeting / smile and see what’s happening: With a little luck, the staff might grant the 50% discount nevertheless.