MacAdam ellipses or SDCM (Standard Deviation of Color Matching) are used to specify color tolerance. MacAdam ellipses refer to the area on a chromaticity diagram that encompasses all colors that the average human eye cannot distinguish from the color at the center of the ellipse. The ellipse's contour represents the just noticeable differences in chromaticity. Energy Star requires a color tolerance of 7 steps MacAdam ellipses, while ERP requires 6 steps. Our lighting products can achieve a color tolerance of 3 steps MacAdam ellipses or even smaller. Smaller MacAdam ellipses indicate less color difference.