How to Add Watermarks and Page Color or Border in Word
You can dress up pages in a document with page borders and background settings. You can line the margins of your pages with borders to give them finished edges or to make certain pages stand out, and you can even create your own page designs using colors and watermarks.
You can also add a background color to your document. This color will only appear in digital copies of the document—Word will not print the page color.
On the Design tab, click the Page Color button.
Select a color.
Page color won't be printed; it will only appear when viewed digitally—as a Word document, PDF, or web page.