Gtk.ColorChooser

const Gtk = imports.gi.Gtk;

let color_chooser = new Gtk.ColorChooser({
    rgba: value,
    use_alpha: value,
});
  

Gtk.ColorChooser is an interface that is implemented by widgets for choosing colors. Depending on the situation, colors may be allowed to have alpha (translucency).

In GTK+, the main widgets that implement this interface are Gtk.ColorChooserWidget, Gtk.ColorChooserDialog and Gtk.ColorButton.