These features are additional extras to the plugin, not related to the themes nor Material Design but simply nice addons for the IDE.
Project View Decorators
This feature is adding decorations to the Project View to mimic the original Material Sublime Theme decorations.
Open and closed directories
When this option is on, files that are opened in the editor and that are edited will have their containing directories have a hollow directory icon (or outline directory) instead of the original icon.
Note: This feature requires Material Icons feature to work.
Note 2: If the Folder decorators option is set, the icon will match the decorator, but outlined.
Theme in Status Bar
This setting adds a “widget” to the status bar to indicate which theme you are currently on. You can also click on it to open the Material Theme Settings.
Since version 2.9.4/2.10.4 you can also see your current accent color.
Themed Title Bar
This setting also allows the theming of the application title bar in Windows 10. To do so, it is actually setting the Windows Accent Color set by Windows.
Note: Since this modifies the color OS-wide, the color set by the plugin will stick even if you close the IDE/uninstall the plugin. Just follow the instructions at https://www.howtogeek.com/225893/how-to-personalize-windows-10s-appearance/ to set it to another color of your choice.
From version 2.5.0 the option came back with support for Mac OS. And unlike in Windows, this does not change the Registry but actually applies the background color to the IDE title bar only!
However it comes with a small price: by activating this option you are consenting to nullify the Dark Window Headers feature from the
Appearance panel introduced since 2018.2.
Q: I’ve disabled the plugin but I still get the themed title bar!
A: This happens because this is not a feature implemented by the plugin, but instead makes use of a feature of the operating system. Therefore even when the IDE is closed the setting will persist. You can change the color of the title bar in Windows by following the instructions at https://www.howtogeek.com/225893/how-to-personalize-windows-10s-appearance/