In the past week I have been visiting Rennes for collaborating on research. Workwise everything went fine, but in the airport I encountered one of my daily struggles: the colors used to indicate if a toilet i occupied or free. What colors make sense? well, obviously red for occupied and green for free! Right? No! As color blind, I can’t see the difference so I have to try the door and see. Okay okay, it’s only a slight inconvenience but it would still be nice I didn’t have to disturb the person occupying the toilet.