色彩論
Over two centuries ago, the effect of color depth perception was first noted by Goethe in his Farbenlehre (Theory of Colours) in which he recognized blue as a receding color and yellow/red as a protruding color. He argued that, "like we see the high sky, the far away mountains, as blue, in the same way a blue field seems to recede…(also) One can stare at a perfectly yellow/red field, then the color seems to pierce into the organ". This phenomenon, now referred to as chromostereopsis, or the stereoptic effect, explains the visual science behind this color depth effect, and has many implications for art, media, evolution, as well as our daily lives in how we perceive colors and objects.