slider.setOpaque(true);
  protected void installDefaults(JSlider slider)  {    UIDefaults defaults = UIManager.getLookAndFeelDefaults();    slider.setForeground(defaults.getColor("Slider.foreground"));    slider.setBackground(defaults.getColor("Slider.background"));    shadowColor = defaults.getColor("Slider.shadow");    highlightColor = defaults.getColor("Slider.highlight");    focusColor = defaults.getColor("Slider.focus");    slider.setBorder(defaults.getBorder("Slider.border"));    thumbHeight = defaults.getInt("Slider.thumbHeight");    thumbWidth = defaults.getInt("Slider.thumbWidth");    tickHeight = defaults.getInt("Slider.tickHeight");    focusInsets = defaults.getInsets("Slider.focusInsets");  }