You can quickly and easily give your document a professional look by applying a document theme. A document theme is a set of formatting choices that include a set of theme colors, a set of theme fonts (including heading and body text fonts), and a set of theme effects (including lines and fill effects).
Important: Document themes that you apply affect the styles that you can use in your document.
On the Page Layout tab, in the Themes group, click Themes.
Click the document theme that you want to use.
If a document theme that you want to use is not listed, click Browse for Themes to find it on your computer or network.
To automatically download new themes, click Enable Content Updates from Office.com.