Use the Dark,Auto,Light background theme setting

[lopezjm2001]

Use the Head Unit background theme setting to also change the background colour theme for the MG4_Control app. The MG4_Control app seems to have a permanent dark mode.

[SliDeeN]

Actually, MG4Control only offers a dark theme.
I can check if it's possible to get a light theme that matches the official launcher's settings.