Transparent JButton taking background of other, how to fix it?

Question

I created a program that includes many invisible JButtons, but when moving the mouse over them, they all take the background for the upper left JButton, which will make it difficult for their actual use. Also, when placing the mouse on the bottom right, everything resets. Any idea why this happens? Thanks.

Images for When initiating the program and When using the mouse

In case it serves, the way I make the buttons (which are extensions of JButton) invisible is by having the paint overriding function do nothing.

public void paint(Graphics g) {

}

Answer 1

As an aside, don't mess with painting methods to get invisibility. Here is how to do it.

private JButton getInvisibleButton() {
    // create a TRANSPARENT image to give the button a size
    BufferedImage bi = new BufferedImage(16,16,BufferedImage.TYPE_INT_ARGB);
    JButton b = new JButton(new ImageIcon(bi));
    b.setBorderPainted(false);
    b.setContentAreaFilled(false);
    b.addActionListener(actionListener);
    // change to false to hide them even when focused
    b.setFocusPainted(true); 
    return b;
}