Thread: For some reason, I am getting a grey background rather than the 'CYAN' I have coded.

However, it shows a CYAN border around the button on the frame. Does anyone know why?

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
 
 
public class Front_ChristmasCard extends JFrame implements ActionListener
{
 
   static String Guestname;
   private boolean cardOpen=false;
   private JButton cardOpenButton = new JButton("Open Card");
 
 
    public Front_ChristmasCard()
    {
       Guestname= JOptionPane.showInputDialog("Enter your name to see your card:");
 
 
       //sets title above window
       setTitle("Marry Christmas " + Guestname);
 
       //     sets layouts, adds buttons and sets background.
       setLayout(new FlowLayout());
       add(cardOpenButton);
       getContentPane().setBackground(Color.CYAN);
 
       //adds listener
       cardOpenButton.addActionListener(this);
 
       //sets size of window
       setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       setSize(700,900);
       setLocation(750,750);
       setVisible(true);
    }
 
 
   public void paint(Graphics g)
   {
      g.drawString("Merry Christmas " + Guestname + "",300, 800);
      g.setColor(Color.white);
      g.fillRect(130,700,460,45);
      g.setColor(Color.red);
      g.fillRect(150,655,420,45);
      g.fillRect(170,615,380,45);
      g.fillRect(190,575,340,45);
      g.fillRect(210,535,300,45);
      g.fillRect(230,495,260,45);
      g.fillRect(250,455,220,45);
      g.fillRect(270,415,180,45);
      g.fillRect(290,375,140,45);
      g.fillRect(310,335,100,45);
      g.fillRect(340,295,40,45);
      g.setColor(Color.white);
      g.fillOval(320,255,140,100);
 
 
 
   }
 
    public void actionPerformed(ActionEvent event)
    {
       if(event.getSource() == cardOpenButton)
       {
          cardOpen = true;
          Inside_ChristmasCard gui= new Inside_ChristmasCard();
 
 
 
       }
 
 
 
 
    }
 
 
   public static void main(String[] args)
   {
       Front_ChristmasCard gui=new Front_ChristmasCard();
   }//main
}//class

I am sorry, but I couldn't understand your answer. Is there any chance you could explain those points more 'amateurally'