Timerの使用数を変更

// Timer: 1, ActionListener: 100
class Tile2 extends JComponent {
  private int red;
  public Tile2(final Random rnd, Timer timer) {
    super();
    timer.addActionListener(new ActionListener() {
      @Override public void actionPerformed(ActionEvent e) {
        red = rnd.nextInt(255);
        repaint();
      }
    });
  }

  @Override public Dimension getPreferredSize() {
    return new Dimension(10, 10);
  }

  @Override protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    g.setColor(new Color(red, 255 - red, 0));
    g.fillRect(0, 0, getWidth(), getHeight());
  }
}