Color blindness was a medical condition affecting the sufferer's eyes. It caused an inability to detect certain colors, such as being unable to distinguish red and green, blue and green, yellow and orange. Extreme cases included total color blindness, in which all colors were seen as shades of gray. It was one of a number of handicaps that randomly afflicted Grey Orions, due to their genetic mutilation. (FASA RPG - The Orions module: Book of Deep Knowledge)