Night mode as Default

OS type and version Rocky 9.4
Webmin version 2.111

On the left sidebar there is an option to switch day/night mode.
How can I set the option so that for all new users it will start with night mode as default?



By default, whatever the root user uses becomes the default for any user on the system. Any time a user changes a palette, it gets saved for that user. You can define the palette for the login page in Theme Configuration: General defaults page.