Can't render background color in JComboBox, after selection.

Question

I don't understand why this problem is so difficult. It is driving me nuts.
If I create a renderer for a Jcombobox, it will correctly render TEXT and COLOR if it is displaying it in the pop up list, but as soon as it has been selected, the combo will render TEXT correctly but will ignore COLOR. I have tried playing around with opacity and with the editors, but it just seems as if JComboBox renderers do not work 100% as expected.
Here is my text code. All I want is for the color of X or Y to be reflected in the selected element :
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import javax.swing.DefaultListCellRenderer;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
public class CustomComboBoxDemo extends JPanel {
    public CustomComboBoxDemo() {
        super(new BorderLayout());
        String[] s = { "1", "2", "3", "4", "5" };
        JComboBox c = new JComboBox(s);
        JComboBox c2 = new JComboBox(s);
        c.setOpaque(true);
        ComboBoxRenderer renderer= new ComboBoxRenderer();
        c.setRenderer(renderer);
        c2.setRenderer(renderer);
        JPanel p = new JPanel();
        p.add(c);
        p.add(c2);
        add(p);
    class ComboBoxRenderer extends DefaultListCellRenderer {
        public ComboBoxRenderer() {
            setOpaque(true);
        public Component getListCellRendererComponent(
                                           JList list,
                                           Object value,
                                           int index,
                                           boolean isSelected,
                                           boolean cellHasFocus) {
             JLabel c = (JLabel)super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
             if (value.toString().equals("3")) {
                 c.setText("X");
                 c.setBackground(Color.RED);
             } else {
                 c.setText("Y");
                 c.setBackground(Color.GREEN);
             return this;
    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("CustomComboBoxDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setContentPane(new CustomComboBoxDemo());
        //Display the window.
        frame.pack();
        frame.setVisible(true);
}

Answer 1

I think the problem has to do with the Alloy look and feel. If I use the Systsem look and feel then the setBackground() method does not colour in the button (just the textfield)
This has fixed my initial problem :
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import javax.swing.DefaultListCellRenderer;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.plaf.basic.BasicComboBoxEditor;
public class CustomComboBoxDemo extends JPanel {
    public CustomComboBoxDemo() {
        super(new BorderLayout());
          try {
               UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
          } catch (Exception e) {
               e.printStackTrace();
        String[] s = { "1", "2", "3", "4", "5" };
        JComboBox c = new JComboBox(s);
        JComboBox c2 = new JComboBox(s);
//        c.setRenderer(aRenderer)
//        c.getEditor().getEditorComponent().setBackground(Color.GREEN);
        c.setBackground(Color.pink);
        c2.setBackground(Color.pink);
//        c2.setBackground(Color.black);
        c.setOpaque(true);
        c2.setOpaque(false);
        ComboBoxRenderer renderer= new ComboBoxRenderer();
        c.setRenderer(renderer);
        c2.setRenderer(renderer);
        JPanel p = new JPanel();
        p.add(c);
        p.add(c2);
        add(p);
    private class MyComboBoxEditor extends BasicComboBoxEditor{
         public Component getEditorComponent(){
              Component comp = super.getEditorComponent();
              comp.setBackground(Color.red);
              return comp;
    class ComboBoxRenderer extends DefaultListCellRenderer {
        public ComboBoxRenderer() {
            setOpaque(true);
        public Component getListCellRendererComponent(
                                           JList list,
                                           Object value,
                                           int index,
                                           boolean isSelected,
                                           boolean cellHasFocus) {
             JLabel c = (JLabel)super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
//             setForeground(Color.green);
//             setBackground(Color.black);
//             list.setForeground(Color.green);
//             list.setBackground(Color.black);
             if (value.toString().equals("3")) {
                 c.setText("X");
                 c.setBackground(Color.RED);
             } else {
                 c.setText("Y");
                 c.setBackground(Color.GREEN);
             return this;
    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("CustomComboBoxDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setContentPane(new CustomComboBoxDemo());
        //Display the window.
        frame.pack();
        frame.setVisible(true);
}