Bagaimanakah saya boleh menukar warna butang dalam Java Swing Berdasarkan Negeri?

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;

public class ButtonColorExample extends JPanel implements ActionListener {

    private static final int N = 4;
    private static final Random rnd = new Random();
    private final Timer timer = new Timer(1000, this);
    private final JButton[] buttons = new JButton[N * N];

    public ButtonColorExample() {
        // Initialize buttons and add them to the panel
        this.setLayout(new GridLayout(N, N));
        for (int i = 0; i < N * N; i++) {
            JButton btn = new JButton("Button " + String.valueOf(i));
            buttons[i] = btn;
            this.add(btn);
        }
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        // Change button colors randomly
        for (JButton btn : buttons) {
            btn.setBackground(new Color(rnd.nextInt()));
        }
    }

    public static void main(String[] args) {
        // Create and configure the frame
        JFrame frame = new JFrame("Button Color Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(new ButtonColorExample());
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);

        // Start the timer to update button colors
        timer.start();
    }
}