To solve the problem that much cost, time and work load are necessary in the formation of the profile of a printing press used in a color management system and there is no index for a period having to renew the profile with respect to a change in the color reproduction state of the printing press.

Color bars for estimating color development are printed on profile forming pattern printed matter and commercial printed matter and the color coordinates value of a profile forming color chart is estimated on the basis of the measuring results of the color bars for estimating the color development of both printed matters to calculate first and second estimated color coordinates values. Both estimated color coordinates values are subjected to differential processing, color fluctuation quantity is calculated to be added to the actually measured color coordinates value of the profile forming color chart, and the profile of the printing press is renewed while the color fluctuation quantity is statistically processed to judge a profile renewing period.