MOBO theme is designed to make your desktop grayish, it is designed to work well with Gnome desktop. This theme has modern colors and animations, left pane is a little bit transparent to make theme look unique. It is currently compatible with Gtk 3.20/3.22/3.24 versions and only works fine in Gnome Desktop, it is pretty simple and elegant. If you find any issues with this theme then report it to developer and hopefully it will get fixed in the next update. If you are using other distribution you can directly download theme from its page and install it manually in ~/.themes folder or /usr/share/themes/. You can use Gnome-tweak-tool to change themes.