Both PowerPoint 2010 and PowerPoint 2007 show the name of the active Theme for a presentation within the Status Bar. We look for a similar option within the PowerPoint 2013 interface. Note that there is no Theme name displayed on the Status Bar. However you can reinstate the Theme name.
To learn more, choose your version of PowerPoint. If we do not have a tutorial for your version of PowerPoint, explore the version closest to the one you use.