The Clean variant replaces the accent-coloured window chrome with a white title bar, a centred title and dark buttons. It is the smaller of the library's two variants: it restyles the window and four other things, and leaves every ordinary control alone.

The Visual Studio variant is the library's broad one: a dark palette, tabs with close buttons, flat menus and thin scrollbars — the look of a tool-window application rather than a document one.

Win10 is not a variant in the sense that Clean and Visual Studio are. There is no Styles/Win10/ folder and no dictionary to merge. What the library ships is a handful of individually keyed styles that you apply one control at a time.

MahApps.Metro does not ship a WinUI variant. There is no Styles/WinUI/ folder, no WinUI style key anywhere in the library, and nothing to merge — in 2.4.11 or on develop.