Peripherally located CRTs: color perception limitations

Colors on a peripherally located CRT (cathode ray tube) may be misperceived. Subjects wrongly identified the color of a peripherally located, 1.3 degrees circle displayed on a CRT 5% of the time if it was blue, 63% of the time if red, and 62% of the time if green. Blue could not be seen further than 83.1 degrees off of the fovea (along the x-axis). Red had to be closer than 76.3 degrees and green nearer than 74.3 degrees before the subjects reported seeing the colors. These average color field dimensions changed with differing subject psychological states due to the observed visual field narrowing (i.e., reduction of the subject's peripheral field of view) in both the relaxed and stressed states. A significant degree of visual field narrowing was noted for the relaxed states (8%), with a trend noted for the stressed state (2%). It is concluded that these color perception limitations must be kept in mind when designing CRT color formats for aircraft cockpits.<<ETX>>