JColorChooserのプレビューパネルにTitledBorderでテキストを表示する

String key = "ColorChooser.showPreviewPanelText";
JTextArea log = new JTextArea();
JCheckBox check = new JCheckBox(key, UIManager.getBoolean(key)) {
  @Override public void updateUI() {
    super.updateUI();
    boolean b = UIManager.getLookAndFeelDefaults().getBoolean(key);
    setSelected(b);
    LookAndFeel laf = UIManager.getLookAndFeel();
    log.append(String.format("%s%n  %s: %s%n", laf, key, b));
    UIManager.put(key, b);
  }
};

JButton button = new JButton("JColorChooser.showDialog(...)");
button.addActionListener(e -> {
  UIManager.put(key, check.isSelected());
  Color c = JColorChooser.showDialog(getRootPane(), "title", null);
  log.append(String.format("color: %s%n", c));
});