A model is described that combines features of both classical and recent theories of color vision and visual adaptation. Neural signals from cone receptors activate gain control mechanisms, which cause neural attenuations to become proportionally greater as receptor signals grow. The attenuated signals are fed to three mechanisms of one of two "opponent colors" systems, and the resulting signals, which are compressed at a final stage, are used to either encode brightness and color appearance or to mediate discriminations and detections of lights. The model provides reasonable accounts of a very diverse body of data.
S. Lee Guth,
"Unified Model For Human Color Perception And Visual Adaptation", Proc. SPIE 1077, Human Vision, Visual Processing, and Digital Display, (15 August 1989); doi: 10.1117/12.952735; https://doi.org/10.1117/12.952735