BugInfo:
========
I have opened a internal frame with yellow background but while changing the look and feel at runtime the background which i set is not effecting.I expected the background color (yellow) which i set should show irrespective of look and feel.

First I launch the application in solaris platform with systems default look and feel then i can see the applied yellow color as frame background.After that i changed to different look and feel then the yellow color for background is not effecting,it shows the look and feel default background color.

I tested the same scenario in windows with winxp look and feel.But i saw the same above behavior.

JDK Info:
=========
java version "1.6.0-rc"
Java(TM) SE Runtime Environment (build 1.6.0-rc-b98)
Java HotSpot(TM) Client VM (build 1.6.0-rc-b98, mixed mode)

Steps to Reproduce:
===================
1. Download the attached java file.
2. Execute the java file.
3. Click on the look and feel menu and choose the any other look and feel.

Expected Behavior:
------------------
The background color should be yellow which has shown by default while launching the application.

Actual Behavior:
----------------
The background color of the internal frame is not showing yellow.
Adding InternalFrameBackgrnd.java here so it will be visible to
the community:

/*
 * InternalFrameBackgrnd.java
 *
 * Created on September 7, 2006, 4:16 PM
 */

/**
 *
 * @author vt152788
 */
import javax.swing.UIManager;
import javax.swing.SwingUtilities;
import javax.swing.UIManager.LookAndFeelInfo;
import javax.swing.ButtonGroup;
import javax.swing.JRadioButtonMenuItem;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class InternalFrameBackgrnd extends javax.swing.JFrame {
    
    /** Creates new form InternalFrameBackgrnd */
    public InternalFrameBackgrnd() {
        lafInfo = UIManager.getInstalledLookAndFeels();
        initComponents();
    }
    
    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:initComponents
    private void initComponents() {
        jDesktopPane1 = new javax.swing.JDesktopPane();
        jInternalFrame1 = new javax.swing.JInternalFrame();
        jMenuBar1 = new javax.swing.JMenuBar();
        lafMenuItem = new javax.swing.JMenu();
        lafButtonGroup = new ButtonGroup();
        lafRadioMenuItems = new JRadioButtonMenuItem [lafInfo.length];
        for(int i= 0; i< lafInfo.length; i++){
            System.out.println("laf name:" + lafInfo[i].getName());
            lafRadioMenuItems[i]=new JRadioButtonMenuItem(lafInfo[i].getName()+" LAF");
            lafButtonGroup.add(lafRadioMenuItems[i]);
            lafRadioMenuItems[i].setActionCommand(lafInfo[i].getClassName());
            lafRadioMenuItems[i].addActionListener(new ActionListener(){
                public void actionPerformed(ActionEvent aevt_){
                    setLAF(aevt_.getActionCommand());
                }
            });
            lafRadioMenuItems[0].setSelected(true);
            lafMenuItem.add(lafRadioMenuItems[i]);
        }

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setTitle("InternalFrameBackgroundIssue");
        jInternalFrame1.getContentPane().setLayout(new java.awt.FlowLayout());

        jInternalFrame1.setBackground(new java.awt.Color(225, 217, 51));
        jInternalFrame1.setIconifiable(true);
        jInternalFrame1.setMaximizable(true);
        jInternalFrame1.setResizable(true);
        jInternalFrame1.setVisible(true);
        jInternalFrame1.setBounds(70, 30, 190, 110);
        jDesktopPane1.add(jInternalFrame1, javax.swing.JLayeredPane.DEFAULT_LAYER);

        getContentPane().add(jDesktopPane1, java.awt.BorderLayout.CENTER);

        lafMenuItem.setText("LookAndFeel");
        jMenuBar1.add(lafMenuItem);

        setJMenuBar(jMenuBar1);

        java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
        setBounds((screenSize.width-400)/2, (screenSize.height-300)/2, 400, 300);
    }// </editor-fold>//GEN-END:initComponents
    
       public void setLAF(String laf){
        final String lafName = laf;
        try{
             SwingUtilities.invokeLater(new Runnable() {
                    public void run(){
                      try{
                           UIManager.setLookAndFeel(lafName);
                           SwingUtilities.updateComponentTreeUI(InternalFrameBackgrnd.this);
                      }catch(Exception exp_){
                           exp_.printStackTrace();
                      }
                    }
                });
        }catch(Exception exp_){
                exp_.printStackTrace();
        }
    } // end of setLAF();
    
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
      try{
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
       }catch(Exception exp_){}
                new InternalFrameBackgrnd().setVisible(true);
    }
    
    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JDesktopPane jDesktopPane1;
    private javax.swing.JInternalFrame jInternalFrame1;
    private javax.swing.JMenuBar jMenuBar1;
    private javax.swing.JMenu lafMenuItem;
    // End of variables declaration//GEN-END:variables
    private LookAndFeelInfo lafInfo[];
    private ButtonGroup lafButtonGroup;
    private JRadioButtonMenuItem lafRadioMenuItems[];
}
There is also a testcase in the SQE repository at Swing_JInternalFrame/Manual/InternalFrameBackground currently failing because of this bug. Once this bug is fixed remove this test from the known failures list, and add it to the normal execution testlist.
Swing_JInternalFrame/Manual/InternalFrameBackground is failing