It changes with light/dark mode. If you want changing wallpapers use something like https://github.com/saint-13/Linux_Dynamic_Wallpapers
How does dark & light mode change on its own? The Bazzite reference I made was I believe I remembered the background changing depending on the time of day or maybe it had a button to switch the modes in the panel with easy access (can't quite remember). On Kinoite I have the screen set to red light automatically at a certain time but the theme doesn't change to dark with it. Is this a possible feature with Plasma?
There is in GNOME
Know idea about kde ... https://invent.kde.org/plasma/plasma-workspace/-/issues/59
Youcan always write a script that runs at dawn and set and change the theme.
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