Please Help Me

[inbox_pub earthlink net]

The following program produces a yellow window.
I am trying to interface a trigger function to change the color and
I have not been successful.

How do I change the color after the window is displayed?

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#include <gtkmm.h>


class Example : public Gtk::Window
{
public:
      Example();
      virtual ~Example();

protected:
      virtual void on_button_quit();

      Gtk::VBox mc_VBox;

      Gtk::HBox mc_HBox;

      Gdk::Color m_Color_Black, m_Color_Red, m_Color_Green, 
m_Color_Yellow;

      Gtk::EventBox m_Light1, m_Light2, m_Light3;

};


Example::Example()
{
      m_Color_Red.set_rgb_p(0.99, 0.00, 0.00);
      m_Color_Yellow.set_rgb_p(0.99, 0.99, 0.00);
      m_Color_Green.set_rgb_p(0.00, 0.99, 0.00);
      m_Color_Black.set_rgb_p(0.00, 0.00, 0.00);


      add(mc_HBox);

      mc_HBox.pack_start(mc_VBox, Gtk::PACK_SHRINK, 0);

      m_Light1.modify_bg(Gtk::STATE_NORMAL, m_Color_Yellow);

      m_Light1.set_size_request(400, 300);

      mc_HBox.add(m_Light1);

      show_all_children();
}


int main(int argc, char *argv[])
{
      Gtk::Main kit(argc, argv);

      Example window;

      Gtk::Main::run(window);

return 0;
}


Example::~Example()
{
}


void Example::on_button_quit()
{
hide();
}

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