int value;       
int green = 2;    
int red = 9;    
int blue = 12;

bool greenOn = false;
bool redOn = false;
bool blueOn = false;
 
void setup() 
{
  pinMode(green, OUTPUT); 
  pinMode(red, OUTPUT); 
  pinMode(blue, OUTPUT);
  Serial.begin(9600); 

  digitalWrite(green, LOW);
}


void loop() 
{
  
  if (Serial.available()) 
  {
    value = Serial.read(); 

    
    
   if (value == 0) 
   {
//      arxhprasino
      if (greenOn == false)
      {
        digitalWrite(green, HIGH);
        greenOn = true;
      }
      else
      {
        digitalWrite(green, LOW);
        greenOn = false;
      }
      
//      telosprasino
    }
    else if (value == 1) 
    {
//       arxh kokkino
      if (redOn == false)
      {
        digitalWrite(red, HIGH);
        redOn = true;
      }
      else
      {
        digitalWrite(red, LOW);
        redOn = false;
      }
//       telos kokkino
    }
     else if (value == 2)
     {
//       arxh mple
      if (blueOn == false)
      {
        digitalWrite(blue, HIGH);
        blueOn = true;
      }
      else
      {
        digitalWrite(blue, LOW);
        blueOn = false;
      }
//        telos mple
     }

  }

  
  
}