title: JLabel.setBackground(Color color) doesn't work?
body: <p>In this SSCCE code:</p>
  
  <p>This method work</p>
  
  <p><code>label.setForeground(Color.GREEN);</code></p>
  
  <p>But this next method doesn't work!  </p>
  
  <p><code>label.setBackground(Color.BLUE);</code></p>
  
  <pre><code>import java.awt.*;
  import javax.swing.*;
  
  public class LabelColorTest extends JPanel
  {
  
      static JLabel label;
      JPanel panel;
  
      public LabelColorTest()
      {
          label = new JLabel();
          label.setVerticalAlignment(JLabel.CENTER);
          label.setHorizontalAlignment(JLabel.CENTER);
          label.setText("Hello world");
  
          panel = new JPanel();
          panel.setLayout(new BorderLayout());
          panel.add(label, BorderLayout.CENTER);
  
          label.setForeground(Color.GREEN);  //HERE
          label.setBackground(Color.BLUE);  //HERE
  
  
          this.setLayout(new BorderLayout());
          this.add(panel);
      }
  
      private static void createAndShowGUI()
      {
          JFrame frame = new JFrame("Hellow world");
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          frame.setSize(400, 250);
          frame.add(new LabelColorTest(), BorderLayout.CENTER);
          frame.setVisible(true);
      }
  
      public static void main(String[] args)
      {
          SwingUtilities.invokeLater(new Runnable()
          {
              public void run()
              {
                  UIManager.put("swing.boldMetal", Boolean.FALSE);
                  createAndShowGUI();
  
              }
          });
      }
  }
  </code></pre>