By default, the PowerPoint 2016 Ribbon area is placed against an orange backdrop. This orange color shows up because the default Office Theme named Colorful is applied to the interface. So why is the Theme called Colorful when it is just a plain orange backdrop? That’s because any Theme you apply to an interface of an Office 2016 program influences all other programs. For instance, Word 2016 sports a blue backdrop while Excel uses green. In addition to the color interface options previously available for all Office applications, Office 2016 has introduced a new Office Theme named Black for the interface color.
Learn about Black Interface in PowerPoint 2016 for Windows.

