#define blu 9
#define rosso 11 
#define verde 10
#define pulsante 2
int stato=0

void setup() {
pinMode(rosso, OUTPUT);
pinMode (verde,OUTPUT );
pinMode(blu, OUTPUT);
pinMode((pulsante, INPUT));
}
void loop() {
   valorepulsante = digitalRead(pulsante);

  switch(stato) {
     csase 0
      statospento();
       break;
    case 1
       statorosso();
        break;
    case 2
       statoverde();
         break;
    case 3
        statoblu();
       break;
  }
    analogWrite(rosso,255);
    analogWrite(verde,0);
    analogWrite(blu,255);


  void statospento(){
    analogWrite(rosso,255);
    analogWrite(verde,0);
    analogWrite(blu,255); 
 }
  void statorosso(){
     analogWrite(rosso,255);
     analogWrite(verde,0);
     analogWrite(blu,255);

  }
  void statoverde() {

    analogWrite(rosso,255);
    analogWrite(verde,0);
    analogWrite(blu,255)

  }
 void statoblu(){ 
   analogWrite(rosso,255);
   analogWrite(verde,0);
   analogWrite(blu,255)

 }

}