int red=28;
int green=27;
int blue=26;
bool lastButtonState = 1;
int currentMode=0;

void setup(){
Serial.begin(115200);
pinMode(3, INPUT_PULLUP);
pinMode(red, OUTPUT);
pinMode(green, OUTPUT);
pinMode(blue, OUTPUT);
turnOffAllLEDs();
}

void loop(){
  int buttonState = digitalRead(3);
  if (buttonState == 0 && lastButtonState == 1) { 
      // Button was pressed, change mode
      currentMode++;
      if (currentMode>3){
        currentMode=0;
      }
      updateLEDs(currentMode);
  }
  lastButtonState = buttonState;
  delay(20);
}

void updateLEDs(int mode) {
  switch (mode) {
    case 0: turnOffAllLEDs(); break; // All LEDs off
    case 1: turnOnBlue(); break;    // Blue on
    case 2: turnOnRed(); break;     // Red on
    case 3: turnOnGreen(); break;   // Green on
  }
}

void turnOffAllLEDs() {
  digitalWrite(red, HIGH);
  digitalWrite(green, HIGH);
  digitalWrite(blue, HIGH);
}

void turnOnBlue() {
  turnOffAllLEDs();
  digitalWrite(blue, LOW);
}

void turnOnRed() {
  turnOffAllLEDs();
  digitalWrite(red, LOW);
}

void turnOnGreen() {
  turnOffAllLEDs();
  digitalWrite(green, LOW);
}