Depending on what kind of printer your computer is hooked up to, you can print your presentation in Color; in Grayscale, which consists of various tones of gray combined with black and white; or in Pure Black and White, which eliminates most of the grays and will use the least printer ink.
This is how you select an option for printing:

Under
Print Preview, click
Options, and point to
Color/Grayscale. Then select from the menu. Your slides will be previewed and printed with that choice applied. Note that if you are printing to a black and white printer, the
Color option becomes
Color (On Black and White Printer), and all the slide's colors are rendered using black, white, and shades of gray.

The first preview example shows a slide that will be printed in color.

The second preview example shows a slide that will be printed in grayscale. While the background is made white, some areas reflect color, such as the horizontal banners under the title and along the bottom of the slide.

And the last preview example shows a slide that will be printed in pure black and white.