By default, this option is set to , which means it adopts the background color currently set by the user on their desktop.
Note: The desktop background color is not the color chosen in the system settings under Personalization -> Colors. It refers specifically to the color selected in Personalization -> Background -> Solid Color. Windows retains the last chosen desktop background color if the background mode is switched to picture or slideshow mode.
To specify a color different from the current desktop color, select from the dropdown box.
By default, this option is set to , meaning the locked desktop will display only the background color (either the current desktop color or a specified color).
If you change it to , the current system background picture (i.e., wallpaper) will be used. If the system background mode is "Solid color", since there is no wallpaper, the above specified background color will be used. If the system background mode is "Slideshow", the currently active picture will be used.
To designate a background image, select from the dropdown box.
This setting determines how the background image is displayed on the screen. The available options are similar to the system background picture fit options.