为什么背景色设置后没有改变
import   java.awt.*;
import   java.util.*;

public   class   Clock   extends   javax.swing.JApplet{
  private   Color   butterscotch=new   Color(255,204,102);
  private   String   lastTime= " ";
 
  public   void   init(){
  setBackground(Color.black);
  }
 
  public   void   paint(Graphics   screen){
    Graphics2D   screen2D=(Graphics2D)screen;
    Font   type=new   Font( "Monospaced ",Font.BOLD,20);
    screen2D.setFont(type);
    GregorianCalendar   day=new   GregorianCalendar();
    String   nowTime=day.getTime().toString();
    screen2D.setColor(Color.black);
    screen2D.drawString(lastTime,5,25);
    screen2D.setColor(butterscotch);
    screen2D.drawString(nowTime,5,25);
    try{
        Thread.sleep(1000);
    }
    catch(InterruptedException   e){
   
    }
    lastTime=nowTime;
    repaint();
  }
}

------解决方案--------------------
不知道是不是这个意思
import java.awt.*;
import java.util.*;

public class Clock extends javax.swing.JApplet{
private Color butterscotch=new Color(111,111,111);
private String lastTime= " ";

public void init(){
setBackground(Color.BLACK);
}

public void changeColor(Color color){
setBackground(color);
}

public void paint(Graphics screen){
Graphics2D screen2D=(Graphics2D)screen;
Font type=new Font( "Monospaced ",Font.BOLD,10);
screen2D.setFont(type);
GregorianCalendar day=new GregorianCalendar();
String nowTime=day.getTime().toString();
screen2D.drawString(lastTime,5,25);
screen2D.setColor(butterscotch);
screen2D.drawString(nowTime,5,25);
try{
Thread.sleep(1000);
}
catch(InterruptedException e){

}
this.changeColor(Color.blue);
this.setVisible(false);
this.setVisible(true);
lastTime=nowTime;
repaint();
}
}