How do I change the color of the selected tab on a JTabbedPane?

All you need to do is set the "TabbedPane.selected" property to the desired color in the UIManager. The following program demonstrates this capability.

import java.awt.*;
import javax.swing.*;

public class TabSample {
  static void addIt (JTabbedPane tabbedPane, String text) {
    JLabel label = new JLabel(text);
    JButton button = new JButton(text);
    JPanel panel = new JPanel();
    panel.add(label);
    panel.add(button);
    tabbedPane.addTab(text, panel);
  }
  public static void main (String args[]) {
    JFrame f = new JFrame("JTabbedPane Sample");
    Container content = f.getContentPane();
    UIManager.put("TabbedPane.selected", Color.white);
    JTabbedPane tabbedPane = new JTabbedPane();
    addIt(tabbedPane, "Tab One");
    addIt(tabbedPane, "Tab Two");
    addIt(tabbedPane, "Tab Three");
    addIt(tabbedPane, "Tab Four");
    addIt(tabbedPane, "Tab Five");
    content.add(tabbedPane, BorderLayout.CENTER);
    f.setSize (300, 200);
    f.setVisible (true);
  }
}