Изменение внешнего вида с помощью "UIManager"
UIManager.getLookAndFeelDefaults().put("TabbedPane:TabbedPaneTab[Enabled].backgroundPainter", new BackgroundPainter(Color.white));
UIManager.getLookAndFeelDefaults().put("TabbedPane:TabbedPaneTab[Enabled+MouseOver].backgroundPainter", new BackgroundPainter(Color.white));
UIManager.getLookAndFeelDefaults().put("TabbedPane:TabbedPaneTab[Enabled+Pressed].backgroundPainter", new BackgroundPainter(Color.white));
UIManager.getLookAndFeelDefaults().put("TabbedPane:TabbedPaneTab[Focused+MouseOver+Selected].backgroundPainter", new BackgroundPainter(Color.white));
UIManager.getLookAndFeelDefaults().put("TabbedPane:TabbedPaneTab[Focused+Pressed+Selected].backgroundPainter", new BackgroundPainter(Color.white));
UIManager.getLookAndFeelDefaults().put("TabbedPane:TabbedPaneTab[Focused+Selected].backgroundPainter", new BackgroundPainter(Color.GRAY));
UIManager.getLookAndFeelDefaults().put("TabbedPane:TabbedPaneTab[MouseOver+Selected].backgroundPainter", new BackgroundPainter(Color.white));
UIManager.getLookAndFeelDefaults().put("TabbedPane:TabbedPaneTab[Pressed+Selected].backgroundPainter", new BackgroundPainter(Color.white));
UIManager.getLookAndFeelDefaults().put("TabbedPane:TabbedPaneTab[Selected].backgroundPainter", new BackgroundPainter(Color.white));
Класс BackgroundPainter
public class BackgroundPainter implements Painter<JComponent> {
private Color color = null;
BackgroundPainter(Color c) {
color = c;
}
@Override
public void paint(Graphics2D g, JComponent object, int width, int height) {
if (color != null) {
g.setColor(color);
g.fillRect(0, 0, width - 1, height - 1);
}
}
}