Themes provide a complete page design for your document, including background designs, font styles, colors, and layouts. To add your own personal touch, you can customize a theme and save it to use on other documents.
If you haven't already applied a theme, click Design > Themes, and then click the one you want to apply.
Customize the theme by changing the colors, fonts, and page colors on the Design tab.
To save your customized theme, click Design > Themes > Save Current Theme.
To apply your theme to another document, click Browse for Themes and look for your theme in the Themes folder.