color_edit_widget->signal_value_changed().connect(sigc::mem_fun(*this,
&studio::Dialog_Color::on_color_changed));
get_vbox()->pack_start(*color_edit_widget);
color_edit_widget->signal_value_changed().connect(sigc::mem_fun(*this,
&studio::Dialog_Color::on_color_changed));
get_vbox()->pack_start(*color_edit_widget);