Force a specific background and accent color This setting configures Windows to use the specified colors for the background and accent. The color values are specified in hex as #RGB. By default, users can change the background and accent colors. If you enable this setting, the background and accent colors of Windows will be set to the specified colors and users cannot change those colors. This setting will not be applied if the specified colors do not meet a contrast ratio of 2:1 with white text. If you disable or do not configure this setting, users will be able to change the background and accent colors.

(1) GPO: Computer Configuration\Administrative Templates\Control Panel\Personalization!Force a specific background and accent color (2) WMI: ###