We use the attached code to adjust the red/blue/green/yellow luminance ratio at three different eccentricity ranges (0 –2°, 2–5°, and 5–10°) based on flicker photometry (Ives, 1907; Bone and Landrum, 2004). Further details of the method are described on our previous publications (Nasr et al., 2016; Nasr and Tootell, 2018).