This is really weird. My husband and I share the same (up-to-date) version of firefox but have different profiles. We are using the same printer, printer driver and presets. I have tons of extensions and he has very few. He doesn't know enough about computers to make any advanced changes in firefox. Here's the problem. When using his profile, we can't get Firefox to print in black and white only. The driver is clearly set for black and white, but pages print in color. This happens even when I start in safe mode using his profile. In my profile and in a "clean" profile I keep around for troubleshooting purposes, Firefox prints in black when we ask it to. I tried his profile on an old version of Firefox (51) that I keep around when I need to use plug-ins and pages still print in color when they're supposed to print in black, so it looks to me as if the issue is clearly with his profile. I tried resetting the print.print (whatever Mozilla said to reset) setting in about:config, but that didn't do anything. BTW the setting print.print_in_color and the printer-specific print_in_color setting are both true, if that means anything. I tried changing them to false, but as soon as I try to print anything with his profile, they revert to true. What setting could have gotten changed that's causing the problem and is there a fix short of rebuilding a new profile for him?