The project started with a simple photo, inspired by the photographic work of Michael Belhadi's shots of Berlin and Alexanderplatz in particular. This one photo became two photos which swiftly became a collection of every single station in the Berlin underground U-Bahn network. All 145 (above-ground) stations.

A Hue Bahn store briefly existed on Etsy selling prints and posters but effort > money, so that's long-since retired.