Not entirely it also uses bits of color ink to make the black and white page look better, at least according to the printer companies who conveniently also benefit by selling you more ink.

There is a few bits you can flip on the Firmware side to fix that.

Woah! I never considered that until now. I'll bet you're right.

If you are happy to live with B&W printing for your untraceable printing needs, maybe you can fill the yellow cartridge with clear ink (not sure if water is OK).

But then, how do B&W laser printer allow for tracing ?