MacOS – How to change default print preference to black and white, system wide

There is a much easier way.

1. Create a Print Preset, with the settings as you want them. Select it.

2. Press the Print button while holding down Alt (Option).

That will force your current settings to be the default for the printer.

What I've done is:

• Use the CUPS interface (http://localhost:631/ - specifically http://localhost:631/admin/#HPColorOptionsPanel) to change the default for Print colors as grey to on.
• From a Print dialog, on the Presets menu choose Show presets...
• Tick Reset Presets menu to "Default Settings" after printing.

When I want a colour print, I go to the 'Colour/Quality' section of the Print Settings dialog and set up the colour options as I want them. I've saved them in a preset, so I can just select a colour printing preset when I want it, but after each job it reverts to black and white.