After changing the black and colour cartridge my printer does not print colour. Tests pages for cleaning the heads and nozzle checks prints correct colours displayed. Yet when trying to print a file with colours it prints out in darker greyscale. Colour cartridge selected in the menu only prints out in greyscale. Black cartridge selected prints, Black. This is baffling me. Contacted Canon and the tech guy is also confused and never heard of this happening. Is someone in this Forum able to assist me to solve this problem, please? I have used all brands of inkjet printer over 20 years and thinks Canon Pixma is an excellent inkjet printer. Of course, I am now a senior pensioner and can ill afford to replace the printer.