The other possible reason is that your profiles are amiss. I printed a B&W the other night after telling PS to let the printer manage the color, and telling the printer driver to not manage the color. Neither one did the management, and I got a color caste. You can also get these if both perform color management.
Let PS manage the color, and turn off color management in the printer driver. Of course, use the correct profile for your ink/paper combination within PS.