Printing apparatus, printing control method, and storage medium

A printing apparatus, comprising:

• an image forming portion which forms a chart image on a sheet conveyed from a sheet feeding deck;
• a color measure portion which performs color measurement by reading the chart image formed by the image forming portion;
• one or more controllers including one or more processors and one or more memories, the one or more controllers configured to:
• generate correction data based on color measurement results of the chart image by the color measurer portion and a reference value;
• and
• perform correction for target image data by using the generated correction data,
• wherein the reference value is obtained by performing color measurement of the chart image on the sheet by the color measure portion, the reference value is registered in association with a first type of sheet, and in a case where the first type of sheet on which the chart image is formed is changed to a second type of sheet, the reference value is updated by performing color measurement of the chart image of the second type of sheet.