ceva culori random java

package fy;

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import java.math.*;
import java.util.Random.*;
public class fy extends Applet implements ActionListener {
    Button but1, but2;
    int x = 0, y = 0;

    public void init() {
        but1 = new Button("Deseneaza");
        add(but1);
        but2 = new Button("Sterge");
        add(but2);
        but1.addActionListener(this);
        but2.addActionListener(this);

    }

    public void actionPerformed(ActionEvent e) {
        Button b = (Button) e.getSource();
        if (b == but1) {

            int R = (int)(Math.random()*255);
            int G = (int)(Math.random()*255);
            int B = (int)(Math.random()*255);
            Color variabila = new Color(R,G,B);
            setBackground(variabila);
            x = 50;
            y = 50;
            repaint();
        } else if (b == but2) {
            x = y = 0;
            repaint();
        }

    }

    public void paint(Graphics g) {
        Color [] randomColors = {Color.blue,Color.white,Color.green};
    //  int nrRand = (int )(Math.random() * 3);

        //System.out.println(nrRand);
        //Color variabila = new Color(R,G,B);
        //setBackground(variabila);
        setForeground(Color.green);
        if (x > 0)
            g.fillOval(x, y, 100, 100);
    }
}