Whether colors may have alpha (translucency).
When ::use-alpha is false, the gdk.rgba.RGBA struct obtained via the gtk.color_chooser.ColorChooser.rgba property will be forced to have alpha == 1.
Implementations are expected to show alpha by rendering the color over a non-uniform background (like a checkerboard pattern).
Builder instance for fluent chaining
Deprecated: Use gtk.color_dialog.ColorDialog and gtk.color_dialog_button.ColorDialogButton instead of widgets implementing gtk.color_chooser.ColorChooser
Set useAlpha property.