Figure 6.

The color-scaling data for 2° spots (which activate all three cone types) minus the data for 0.1° spots (which activate L and M but not S cones) show the contribution made by S cones to color appearance. (A) The results for green and blue (centered around 180° on the x axis) are shown. Adding S cones and thus S_o cells makes the region from 90° to 180° more blue and less green and the region from 180° to 270° more green and less blue. (B) Comparable data for yellow and red (centered around 360°).