#define r 2
#define g 4
#define b 5
#define btn 13

int counter;
int lbs = LOW;
unsigned long lbt = 0;
const unsigned long dly = 500;

void setup() {
  pinMode(r, OUTPUT);
  pinMode(g, OUTPUT);
  pinMode(b, OUTPUT);
  pinMode(btn, INPUT_PULLUP);
}

void loop() {
  int btnState = digitalRead(btn);

  if (btnState == LOW && lbs == HIGH && (millis() - lbt) > dly) {
    lbt = millis();
    counter = (counter + 1) % 9;
  }

  if (counter == 1) {
    digitalWrite(r, LOW);
    digitalWrite(g, LOW);
    digitalWrite(b, LOW);
  }
  if (counter == 2) {
    digitalWrite(r, LOW);
    digitalWrite(g, LOW);
    digitalWrite(b, HIGH);
  }
  if (counter == 3) {
    digitalWrite(r, LOW);
    digitalWrite(g, HIGH);
    digitalWrite(b, LOW);
  }
  if (counter == 4) {
    digitalWrite(r, LOW);
    digitalWrite(g, HIGH);
    digitalWrite(b, HIGH);
  }
  if (counter == 5) {
    digitalWrite(r, HIGH);
    digitalWrite(g, LOW);
    digitalWrite(b, LOW);
  }
  if (counter == 6) {
    digitalWrite(r, HIGH);
    digitalWrite(g, LOW);
    digitalWrite(b, HIGH);
  }
  if (counter == 7) {
    digitalWrite(r, HIGH);
    digitalWrite(g, HIGH);
    digitalWrite(b, LOW);
  }
  if (counter == 8) {
    digitalWrite(r, HIGH);
    digitalWrite(g, HIGH);
    digitalWrite(b, HIGH);
  }
  lbs = btnState;
}