Applying a Theme to an existing presentation is easy — and you’ll find that plenty of Themes are already contained inside Office 2013. In PowerPoint 2013, these Themes can be found in Design tab of Ribbon. The same Themes that you apply in PowerPoint can also be applied in Word and Excel — in both of these programs, the way of accessing Themes gallery is different from that of PowerPoint.
Learn how to apply Themes in PowerPoint, Word, and Excel 2013 for Windows.

