The Black Only mode forces printer to print black and white only. The printer won't print in color for internal pages as well such as Print Quality Test Pages.
Ways to check if Black Only is enabled
Navigate to Settings > Print > Quality > Print Mode and check whether it is set to "Black and White" then change it to "Color".
Navigate to Settings > Device > Maintenance > Configuration Menu > Print Configuration > Black Only Mode. Make sure this option is unchecked.
Navigate to Settings > Security > Manage Permissions > Function Access > Color Print. Make sure this option has a check mark.
If all options above are set to Color but printer won't print in Color, contact Lexmark Technical Support for further assistance.
LEGACY ID: HO4131
The device starts up into a blank or black control panel screen after replacing the main system controller board.
Lexmark CX/CS72x and XC/Cxxxx: Print Quality Diagnosis ? Printer Not Printing Black