FULL PRODUCT VERSION :
java version "1.5.0_05"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_05-b05)
Java HotSpot(TM) Client VM (build 1.5.0_05-b05, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [verziószám: 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
On initialization, I set a JLabel's background color, to let's say red.
If I use a custom cellRenderer for a JComboBox that returns this red JLabel, the JComboBox will change the label's background color, so that it will not display red

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I expect the JComboBox renderin mechanism to NOT change the Color of the JLabel I use
ACTUAL -
It changes the Color from red (in this case) to javax.swing.plaf.ColorUIResource[r=163,g=184,b=204]

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.awt.Color;
import java.awt.Component;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.ListCellRenderer;

public class Test3 extends javax.swing.JFrame implements ListCellRenderer{
    JLabel renderer=new JLabel();
    
    public Test3() {
        initComponents();
        renderer.setBackground(Color.red);
        jComboBox1.setRenderer(this);
        jComboBox1.revalidate();
        setSize(100,70);
        setLocationRelativeTo(null);
    }
    
    public Component getListCellRendererComponent(JList list,Object value,int index,boolean isSelected,boolean cellHasFocus){
        //renderer.setBackground(Color.red);
        renderer.setText(value.toString());
        renderer.setOpaque(isSelected);
        renderer.setForeground(isSelected ? Color.white : Color.black);
        System.out.println("Background Color of JLabel: "+renderer.getBackground());
        return renderer;
    }
    
    private void initComponents() {
        jComboBox1 = new javax.swing.JComboBox();

        getContentPane().setLayout(null);

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        jComboBox1.setModel(new javax.swing.DefaultComboBoxModel(new String[] { "1", "2", "3" }));
        getContentPane().add(jComboBox1);
        jComboBox1.setBounds(0, 0, 105, 22);

        pack();
    }
    
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Test3().setVisible(true);
            }
        });
    }
    
    private javax.swing.JComboBox jComboBox1;
    
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
You need to set the Color of the JLabel each time getCellRendererComponent is called