gtk:css-provider-prefers-color-scheme (object)

object -- a gtk:css-provider object
mode -- a gtk:instance-color-scheme value

The accessor for the prefers-color-scheme slot of the gtk:css-provider class gets or sets the color scheme used for rendering the user interface. The UI can be set to either :light or :dark mode. Other values will be interpreted the same as the :light value.

This setting is be available for media queries in CSS:

@media (prefers-color-scheme: dark) {
  // some dark mode styling
}  

Changing this setting will reload the style sheet.

Since 4.20