Discussion on:

Add color or a picture to a Word document's background

I've been doing this for years. The way to make your document's content stand out from the background is to:
1. - If you're using just a color, go into Fill Effects and on the Gradient tab, slide the Dark -- Light bar to light so the color isn't overpowering, just subtle.
2. - For images, add them to the HEADER, Select Insert Header, then on the Insert ribbon, select add image (or cilpart). Once the image is in the document, right-click, select Format Picture| and select the Shadow option. Play with the Transparency slider until you get the effect you want.