I know that I can fade in a panel, by adding the alpha value to the background color & a timer. But how can I fade in a panel with child components (like a JLabel)?

EDIT

_fadeTimer = new Timer(40, new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            if (_alpha == 255) {
                _fadeTimer.stop();
            } else {
                pnl_hint.setBackground(new Color(
                        bgColor.getRed(),
                        bgColor.getGreen(),
                        bgColor.getBlue(),
                        (_alpha += 1)));

                pnl_hint.updateUI();
            }
        }
    });
    _fadeTimer.start();