Figure 34. Themes Group
Each theme is a set of design elements that stores color, fonts and graphics including lines and fill effects. The colors assigned to a them contain four text and background colors, six accent colors, and two hyperlink colors.
In addition to using the predefined themes, you can also create your own by customizing an existing theme and giving it a new name.
Applying a Document Theme
Click Themes in the Themes group on the Page Layout tab
Hover your mouse over each Theme
Once you find a theme you like, just click it