how to add best colors in netbeans jframe code example

Example 1: how to set background color in jframe in java

package Exaple;

import java.awt.Color;

import javax.swing.JFrame;

public class Window {

	public static void main(String[] args) {
		
		JFrame frame = new JFrame(); 
		frame.setExtendedState(JFrame.MAXIMIZED_BOTH); 
		frame.setVisible(true);
		frame.setTitle("Expaple");
		frame.setBackground(Color.BLUE);
	}

}

Example 2: jframe color

private JFrame frame;
frame.getContentPane().setBackground(Color.BLACK);