The Sellaronda is a famous and very nice ski route that loops around the massif of the Sella mountain range, of the Dolomites. You can ski the route in two directions. The clockwise route of the Sellaronda is marked on the map and at the pistes in orange. The counter clockwise route is marked in green. Red and green is quite difficult for colorblinds, but differentiating orange and green is nearly impossible!
There are additional small directional arrows, but they are only visible from close up and by far not attached to each mark. So colorblinds are not able to ski there without help. How about changing one of both colors into blue or black?