//identify which pins control LED'S
const int ledPinRed = 2;
const int ledPinBlue = 4;

void setup() {
  // set up pins 2 & 4 to outputs 
  pinMode(ledPinRed, OUTPUT);
  pinMode(ledPinBlue, OUTPUT);

}

void loop() {
  // flash red once
  digitalWrite (ledPinRed, HIGH);
  delay (500);
  digitalWrite (ledPinRed, LOW);
  delay (500);

  // flash red and blue
  digitalWrite(ledPinRed, HIGH);
  digitalWrite(ledPinBlue, HIGH);
  delay (1000);
  digitalWrite(ledPinRed, LOW);
  digitalWrite(ledPinBlue, LOW);
  delay(500);
}