Hi, I'm trying to figure out exactly what colors a white light (i.e. the Sun) would look like to an observer traveling at varying relativistic velocities. Yes, moving away from it - red shift. Moving towards it - blue shift. In more detail, the human eye has a limited varying-amplitude bandwidth that it can perceive between red to violet. The Sun emits a bandwidth including and extending beyond the human visual color range. With motion away from the Sun, the Sun's apparent emission band shifts some ultraviolet into the perceptible violet or blue and some perceptible red drops off into the imperceptible infrared and all wavelengths in between shift as well. With motion toward the Sun, the Sun's apparent emission band shifts some infrared into the perceptible red/orange range and some blue/violet is shifted into the imperceptible ultraviolet. Has anyone come across an actual study of what the Sun would actually look like in terms of human perception of color with such motions?