Spatial properties of red-green and yellow-blue perceptual opponent-color response

Opponent color responses for an equal illuminance spectrum were measured for field size from 10' to 2 degrees, by means of a hue cancellation procedure. Results showed that when the field diameter was increased, the red and yellow response relatively increased and the green and blue response relatively decreased. There existed a different spatial property between the red-green and yellow-blue opponent-color response function. The results were compared with the optical density hypothesis of the cone visual pigments and with the neurophysiologically obtained receptive field properties of opponent-color cells.