This paper proposes a novel approach to objectively evaluate the severity of color separation based on the value of l ab : urn:x-wiley:2168-0159:sdtp14977:equation:sdtp14977-math-0001 The Max[l ab ] and polar diagram of l ab are used to quantify the severity and reproduce the distribution of color separation, respectively, which are consistent with the visual results. In this way, the phenomenon of color separation can be evaluated more objectively and comprehensively.