void setup() {
  pinMode(13, OUTPUT);
}

void loop() {  
  int red = 13, green = 12, blue = 11;
  digitalWrite(red, HIGH);
  digitalWrite(green, LOW);
  digitalWrite(blue, LOW);
  delay(3000);
  digitalWrite(red, HIGH);
  digitalWrite(green, HIGH);
  digitalWrite(blue, LOW);
  delay(1000);
  digitalWrite(red, LOW);
  digitalWrite(green, HIGH);
  digitalWrite(blue, LOW);
  delay(3000);
}