It is Saturday morning, in a housing development of single-family homes. In one of the gardens, a man has been aiming a high-pressure water jet at the terrace tiles for a while. With each pass, the dirt accumulated over months disappears. The machine is yellow and black. A few streets away, a neighbor is using a similar device to make their car rims shine. It is also yellow and black. Meanwhile, inside another house, a woman is running a machine over the windows to clean them without leaving any marks. Yellow and black.