Reading a Button Press

const int buttonPin = 3;
const int redPin = 11;
const int greenPin = 10;
const int bluePin = 9;


int counter = 0;
void setup()
{
  pinMode(buttonPin, INPUT);
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
}


void loop()
{
  int buttonState;
  buttonState = digitalRead(buttonPin);

  if (buttonState == LOW) // light the LED
  {
    counter++;
    delay(150);
  }

  if (counter == 0)
  {
    digitalWrite(redPin, LOW);
    digitalWrite(greenPin, LOW);
    digitalWrite(bluePin, LOW);
  }
  
  else if (counter == 1)
  {
    digitalWrite(redPin, HIGH);
    digitalWrite(greenPin, LOW);
    digitalWrite(bluePin, LOW);
  }

  else if (counter == 2)
  {
    digitalWrite(redPin, LOW);
    digitalWrite(greenPin, HIGH);
    digitalWrite(bluePin, LOW);
  }

  else if (counter == 3)
  {
    digitalWrite(redPin, LOW);
    digitalWrite(greenPin, LOW);
    digitalWrite(bluePin, HIGH);
  }

  else
  {
    counter = 0;
  }
}