There can be several reasons for Canon printer not printing color. These can be:
Insufficient ink: Check that the cartridge has enough ink to give a color print.
Clogged nozzle and print head: Check for the clogs in the nozzle and print head that may be causing the issue.
Wrong settings: Check that the printer settings are not on grayscale and are configured to color printing.
If these are not the issues, please reach out to the Canon support team for help.