JSliderのUIや色を変更する

class TriangleSliderUI extends MetalSliderUI {
  @Override public void paintThumb(Graphics g) {
    Graphics2D g2 = (Graphics2D) g.create();
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    g2.fillOval(thumbRect.x, thumbRect.y, thumbRect.width, thumbRect.height);
    g2.dispose();
  }

  @Override public void paintTrack(Graphics g) {
    int cx, cy, cw, ch;
    int pad;
    Rectangle trackBounds = trackRect;
    if (slider.getOrientation() == SwingConstants.HORIZONTAL ) {
      Graphics2D g2 = (Graphics2D) g.create();

// ...

slider2.setUI(new MetalSliderUI() {
  @Override protected void paintHorizontalLabel(Graphics g, int v, Component l) {
    JLabel lbl = (JLabel) l;
    lbl.setForeground(Color.GREEN);
    super.paintHorizontalLabel(g, v, lbl);
  }
});
slider2.setForeground(Color.BLUE);