How do you hide slide objects if you're printing in color? The grayscale settings apply only when you print in black and white or in grayscale.
To hide slide objects from color printing, use the option called Omit background graphics from master. This works whether you print in color, in grayscale, or in black and white.
You find it in the Background dialog box, opened from the Format menu.
When you select this option and click Apply to All, it hides all graphics that are on the slide masters (slide master and title master) for all your slides. Not just background graphics, as the name suggests. All graphics.
You can also use this option to hide master graphics on selected slides. Imagine you have a company logo on the master slides; however, one slide in the show contains another set of graphics, which you want to print, that look crowded with the logo. Better to hide the logo on that one slide. To do so, you'd select the slide and apply the Omit background graphics from master option, clicking Apply instead of Apply to All.
This option hides graphics in slide shows too, not just from printing. To view the hidden graphics in your show, clear the Omit background graphics from master check box first.
Careful You can't hide graphics by using the Background printing command in the Options dialog box, opened from the Tools menu. That command doesn't affect what shows or prints on your slides at all.