int red = 6;
int green = 3;
int blue = 5;

int but = 12;
int count = 0;
int state, old_state;

void setup() {

pinMode(red, OUTPUT);
pinMode(green, OUTPUT);
pinMode(blue, OUTPUT);
pinMode(but, INPUT_PULLUP);

}


void knopka(){

  state = digitalRead(but);

  if(state == 1 && old_state == 0){

    count = count + 1;
    delay(200);

  }

  if(count == 4){

    count = 0;

  }

  old_state = state;

}

void loop() {
  // put your main code here, to run repeatedly:

  knopka();  

if (count == 1 ){
  digitalWrite(red, HIGH);
  digitalWrite(green, LOW);
  digitalWrite(blue, LOW);
}
if (count == 2){
  digitalWrite(green, HIGH);
  digitalWrite(red, LOW);
  digitalWrite(blue, LOW);
}
if (count == 3){
  digitalWrite(blue, HIGH);
  digitalWrite(red, LOW);
  digitalWrite(green, LOW);
}
if (count == 0){
  digitalWrite(green, LOW);
  digitalWrite(red, LOW);
  digitalWrite(blue, LOW);
}

}