To easily check a difference between a color space applied to print data created by application and a color space applied to application data.

An image forming system includes a printING control device 1, including an application corresponding to predetermined application data, and an image forming apparatus 2 which can perform direct printing of application data input from the printing control device 1, and printing of print data created by the application based on the application data. The printing control device 1 includes a printing data reading means 12, which reads the print data created by the application based on the application data; an application data reading means 11 which reads the application data itself; and a color space comparison means 14; which compares the color space applied to the print data with the color space applied to the application data.