When you create a new presentation in PowerPoint 2013, you may typically see a single slide with a white background. Alternatively, if you open any of your existing presentations, the background of the slides may be in a different color or fill depending upon the Theme that the presentation is based upon. You can always change this slide background to a picture, a solid color, a pattern, or even a gradient. However, even without exploring all those options, there are twelve Background Styles that PowerPoint offers for every presentation by default. These styles are all coordinated and also designed to work well as a set of complementary backgrounds. You can change your presentation slides to follow any of these background styles by following the steps explained here.