int inPin = 4;
int redPin = 6;
int greenPin = 5;
int bluePin = 3;
int reading;
int previous = LOW;
int bop = 0;
long time = 0;
long debounce = 200;

void setup()
{
  pinMode(inPin, INPUT);
}

void loop()
{
  reading = digitalRead(inPin);
  if (reading == HIGH && previous == LOW && millis() - time > debounce) {
    if (bop == 3)
      bop = 0;
    else
      bop++;

    time = millis();
}

  switch (bop) {
    case 0:
      analogWrite(redPin, 0);
      analogWrite(greenPin, 0);
      analogWrite(bluePin, 0);
    break;
    case 1:
      analogWrite(redPin, 255);
      analogWrite(greenPin, 0);
      analogWrite(bluePin, 0);
    break;
    case 2:
      analogWrite(redPin, 0);
      analogWrite(greenPin, 255);
      analogWrite(bluePin, 0);
    break;
    case 3:
      analogWrite(redPin, 0);
      analogWrite(greenPin, 0);
      analogWrite(bluePin, 255);
    break;
  }
  previous = reading;
}