If you are using the modern "Media Player" app (the successor to Groove Music and the legacy WMP), it support a native dark theme: Media Player (Settings) in the bottom-left corner. Personalization 2. Custom Skins (Legacy WMP 12)
: A modern adaptation that provides high-resolution dark and light surface options like "Mat" and "Glass". How to Apply a Skin: windows media player 12 dark theme
For a true dark visual overhaul, you can use the feature. This changes the "Now Playing" mode but does not usually apply to the full Library window. Access Skins : In WMP12, press Alt > View > Skin Chooser . If you are using the modern "Media Player"
Windows Media Player 12 does have a native, built-in "Dark Mode" toggle in its settings windows media player 12 dark theme