int red = 14;
int yellow = 9;
int blue = 5;


void setup() {

  pinMode(blue, OUTPUT);   //set pin as output , blue led
  pinMode(red, OUTPUT);   //set pin as output , red led
  pinMode(yellow, OUTPUT);   //set pin as output , yellow led

  Serial.begin(9600);    //start serial communication @9600 bps
  }

void loop(){
  
  if(Serial.available()){  //id data is available to read

    char val = Serial.read();

    if(val == 'r'){       //if r received
      digitalWrite(red, HIGH); //turn on red led
      }
    if(val == 'b'){       //if b received
      digitalWrite(blue, HIGH); //turn on blue led
      }
    if(val == 'y'){       //if y received
      digitalWrite(yellow, HIGH); //turn on yellow led
      }
    if(val == 'f'){       //if f received
      digitalWrite(red, LOW); //turn off all led
      digitalWrite(yellow, LOW);
      digitalWrite(blue, LOW);
      }      
    }
  }