@Override void setBackgroundColor(long /*int*/ context, long /*int*/ handle, GdkRGBA rgba) { if (OS.GTK_VERSION >= OS.VERSION(3, 16, 0)) { String css = "GtkToolbar {background-color: " + gtk_rgba_to_css_string(rgba) + "}"; gtk_css_provider_load_from_css(context, css); } else { super.setBackgroundColor(context, handle, rgba); } }