“Smart Lookup” is already available in Word and Outlook, and now it’s been added to Excel and PowerPoint. The ribbon tab text is no longer in all caps and hover states on the ribbon tabs have been added. For those of you that really don’t like the light theme or simply can’t use it, Office 2016 introduces improvements to the Dark theme that makes it easier to use the interface, including better readability in Word’s navigation pane and several Outlook readability fixes (white text on light background, dark text on dark background, and disabled text being unreadable). The light theme that’s been available in Office may be unusable for some users.