为什么setForeground改不了button的颜色

import java.awt.Frame;
import java.awt.Color;
import java.awt.Button;
import java.awt.FlowLayout;
public class Example
{
    public static void main(String[] args)
    {
        Frame f=new Frame();
        Color c=new Color(255,255,0);
        f.setBackground(c);
        f.setSize(500,500);
        f.setLocation(300,300);
        //f.setLayout(new FlowLayout());
        Button button=new Button("");
        f.setLayout(null);
        button.setForeground(Color.cyan);
        //button.setBackground(Color.GREEN);
        button.setBounds(50,50,100,100);
        //button.setSize(200,200);
   
        f.add(button);
        
        f.setVisible(true);
    }
}