int redPin = 13;
int greenPin = 12;
int bluePin = 11;

void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
}

void loop() {
  // Blink red
  digitalWrite(redPin, HIGH);
  delay(1000);
  digitalWrite(redPin, LOW);
  delay(1000);

  // Blink green
  digitalWrite(greenPin, HIGH);
  delay(1000);
  digitalWrite(greenPin, LOW);
  delay(1000);

  // Blink blue
  digitalWrite(bluePin, HIGH);
  delay(1000);
  digitalWrite(bluePin, LOW);
  delay(1000);
}