Relative sensitivity for yellow and blue was determined by hue cancellation, using the method of constant stimuli. Measurements were made with a 1° stimulus at the fovea, 2° above the fovea, and every 4° along the upper vertical meridian out to 18° at three luminance levels (0.5, 0.1, and 0.01 ft-L). Relative yellow-blue sensitivity remained much the same from fovea to periphery for the two highest light levels. At the lowest luminance level there was a slight increase in relative blue sensitivity in the near periphery and a progressive decrease in relative yellow sensitivity as the peripheral angle increased. The variability of color discrimination increased greatly as luminance decreased and the peripheral angle increased.
SEYMOUR WEISSMAN and JO ANN S. KINNEY, "Relative Yellow-Blue Sensitivity as a Function of Retinal Position and Luminance Level," J. Opt. Soc. Am. 55, 74-77 (1965)