With "reverse graffiti" murals are created by cleaning up soot. Cologne wants to fight this with advertisements – the Green Youth scoffs at it.
Clean thing: Reverse Graffiti, here in San Francisco. Image: Frankenhut / License: CC BY 2.0
That Cologne is a rather dirty place was already noted by the Scottish philosopher David Hume in his 18th-century travelogues – today, this is still considered the consensus. Nevertheless, many of its inhabitants consider the old city on the Rhine to be the most beautiful in Germany, usually with the remark that there is more to it than mere surface. Because Kolle, as they also like to sing there, Kolle is after all: e Jefohl.