A control device estimates a color verification result by using the following method. The method includes the steps: 1, obtaining a first set of color values by using measurements of a color chart printed by a printer without color management; 2, calculating second and third sets of color values based on increased color gamut and reduced color gamut of the printer due to a conditional change of the printer; 3, creating a first to third printer-profiles by using the first to third sets of color values; 4, calculating theoretical reference values of target color values and first to third theoretical color values by using the first to third printer-profiles; 5, calculating first to third color differences by using the theoretical reference values and the first to third theoretical color values; 6, obtaining an estimated result of the color verification by comparing the first to third color differences with a preset standard value; and 7, outputting the estimated result.