int const LED_PIN_R = 2;
int const LED_PIN_G = 1;
int const LED_PIN_B = 0;

void setup() {
  pinMode(LED_PIN_R, OUTPUT);
  pinMode(LED_PIN_G, OUTPUT);
  pinMode(LED_PIN_B, OUTPUT);
}

void loop() {
  digitalWrite(LED_PIN_R, HIGH);
  delay(1000);
  digitalWrite(LED_PIN_G, HIGH);
  delay(1000);
  digitalWrite(LED_PIN_B, HIGH);
  delay(1000);
  digitalWrite(LED_PIN_R, LOW);
  delay(1000);
  digitalWrite(LED_PIN_G, LOW);
  delay(1000);
  digitalWrite(LED_PIN_B, LOW);
  delay(1000);
}