const int redPin = 9, greenPin = 10, bluePin = 11;
const int buttonPin = 2;
int buttonState = 0, lastButtonState = 0;
int currentColor = -1; 

void setup() {
  for (int pin = redPin; pin <= bluePin; pin++)
    pinMode(pin, OUTPUT);
  pinMode(buttonPin, INPUT);
}

void loop() {
  buttonState = digitalRead(buttonPin);
  
  if (buttonState != lastButtonState) {
    delay(50);
    
    if (buttonState == HIGH) {
      currentColor = (currentColor + 1) % 4; 
      changeColor(currentColor);
    }
  }
  
  lastButtonState = buttonState;
}

void changeColor(int color) {
  if (color == 0) {
    turnOnRed();
  } else if (color == 1) {
    turnOnGreen();
  } else if (color == 2) {
    turnOnBlue();
  } else if (color == 3) {
    turnOffRGB();
  }
}

void turnOnRed() {
  digitalWrite(redPin, HIGH);
  digitalWrite(greenPin, LOW);
  digitalWrite(bluePin, LOW);
}

void turnOnGreen() {
  digitalWrite(redPin, LOW);
  digitalWrite(greenPin, HIGH);
  digitalWrite(bluePin, LOW);
}

void turnOnBlue() {
  digitalWrite(redPin, LOW);
  digitalWrite(greenPin, LOW);
  digitalWrite(bluePin, HIGH);
}

void turnOffRGB() {
  digitalWrite(redPin, LOW);
  digitalWrite(greenPin, LOW);
  digitalWrite(bluePin, LOW);
}