Cacher is the code snippet organizer for pro developers

import javax.swing.*;

class First{
    public static void main(String args[]){

        Second gui = new Second();
        gui.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        gui.setSize(300, 200);
        gui.setVisible(true);

    }
}

import javax.swing.*;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import java.awt.*;

public class Second extends JFrame {

    private JList list;

    // Creating a visual array so the user can select
    private static String[] colornames = {"black", "blue", "red", "white"};
    // Creating a background array so java can understand
    private static Color[] colors = {Color.BLACK, Color.BLUE, Color.RED, Color.white};

    // Creating the constructor
    public Second(){

        // Setting title
        super("Title");
        // Setting layout
        setLayout(new FlowLayout());

        // Creating the list with the options of the colornames array
        list = new JList(colornames);
        // Setting the visible row count
        list.setVisibleRowCount(4);
        // Setting selection model, which lets us select a set amount of options ( in this case 1 )
        list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        // Adding a scrollpane with the options of our list
        add(new JScrollPane(list));

        // Creating a selection listener with an anonymous class
        list.addListSelectionListener(
                new ListSelectionListener() {

                    public void valueChanged(ListSelectionEvent e) {
                        // Accessing the content pane which is the visual on top of the background
                        // which is needed to access the Background
                        // & Then setting the background color based on the selected index
                        getContentPane().setBackground(colors[list.getSelectedIndex()]);

                    }
                }
        );
    }

}