1. Color blindness, or color vision deficiency, is the inability or decreased ability to see color, or perceive color differences, under normal lighting conditions. There are two major types of color blindness: those who have difficulty distinguishing between red and green, and who have difficulty distinguishing between blue and yellow
2. in 1897, by Jan Szczepanik. He was polish
3) red-MARS, blue- EARTH, green -- ??? nu stiu