To set different desktop backgrounds on Windows 10, navigate to Settings > Personalization > Background, then right-click the ...

Dark Mode is one of the popular modes and it is also available with Windows 11. Dark mode in Windows 11 or Windows 10 delivers a near ... Here you can enable wallpaper and theme switch.

When creating or modifying themes using Windows 11/10 Personalization feature, you must have changed the wallpaper ... else or want to copy it to another computer, there is no direct option.