Version 11.3 includes a new Office 2016-inspired appearance theme. This is also the default appearance theme for new installations. We haven't added a ribbon menu yet, but otherwise the look-and-feel is very similar to Office 2016 and integrates nicely with the aesthetics of Windows 10.
If the blue in this new theme is too bright for you, the previous default theme is still provided, along with 17 other appearance themes. The previous theme is named "VueMinder.isl" and can be selected in the Appearance Options, accessed via the Options menu in the Pro and Ultimate versions (not Lite).