ABSTRACT
Throughout history there have been different approaches to pursuing a better understanding of color and human color vision, depending on the phenomena one wanted to explain. For more than 100 years, up to the end of the twentieth century, the opponent-color theory and the three-color theory of human color vision challenged each other's validity. Both were based upon observations and experiments, although of different kinds. Here, we shall see how they may be reconciled. The Young-Helmholtz three-color theory has led to many controversies and misunderstandings due to confusion of languages that describe physical, biological, and psychological phenomena. There is an increasing awareness of the complicated relationships between stimuli, neural processes, and color perception, but still one can hear teachers claim that activation of the long wavelength sensitive L-cone receptors evokes a red percept, activation of M-cones a green color, and the activation of short wavelength sensitive S-cones leads to the perception of blue. In scientific circles, however, this ancient idea gave way to a more modern form in the three-receptor theory, where the three cone types are defined as linear light detectors with different spectral sensitivities, making trichromatic color matching and color technology so successful.
