java swing setting frame background color not working

I am trying to create a tic tac toe game using java swing. I created a frame and set its background to a color. The problem is that the background color of the frame is not changing, I tried using other colors but the background color is always white. here is the code:

public class TicTacToe implements ActionListener {
    Random random = new Random();
    JFrame frame = new JFrame();
    JPanel title_panel = new JPanel();
    JPanel button_panel = new JPanel();
    JLabel textField = new JLabel();
    JButton[] button = new JButton[9];
    boolean player1_turn;

    TicTacToe () {
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(800,800);
        frame.setVisible(true);
        frame.setTitle("Tic Tac Toe");
        frame.setLayout(new BorderLayout());
        frame.getContentPane().setBackground(Color.BLACK);


        textField.setBackground(new Color(0x084887));
        textField.setForeground(new Color(0xF58A07));
        textField.setText("Tic-Tac-Toe");
        textField.setFont(new Font("Ink Free",Font.BOLD,75));
        textField.setOpaque(true);
        textField.setHorizontalAlignment(JLabel.CENTER);


        title_panel.setLayout(new BorderLayout());
        title_panel.setBounds(0,0,800,100);


        title_panel.add(textField, BorderLayout.NORTH);
        frame.add(title_panel);
    }
}