void setup() {
  pinMode(8, OUTPUT); 
  pinMode(9, OUTPUT); 
  pinMode(10, OUTPUT); 
}

void loop() {
  // put your main code here, to run repeatedly:
  analogWrite(8,0);
  analogWrite(9,255);
  analogWrite(10,255);
  delay(500);
  analogWrite(8,255);
  analogWrite(9,255);
  analogWrite(10,0);
  delay(500);
  analogWrite(8,255);
  analogWrite(9,0);
  analogWrite(10,255);
  delay(500);
  analogWrite(8,255);
  analogWrite(9,255);
  analogWrite(10,255);
  delay (500);
}