int R=21;
int G=19;
int B=18;
 void colorDisplay(char x)
 {
  if(x=='r')
    {
      Serial.print(x);
      digitalWrite(R,LOW);
      digitalWrite(G,HIGH);
      digitalWrite(B,HIGH);
    }
  else  if(x=='g')
    {
      digitalWrite(G,LOW);
      digitalWrite(R,HIGH);
      digitalWrite(B,HIGH);
    } 
  else if(x=='b')
    {
      digitalWrite(B,LOW);
      digitalWrite(G,HIGH);
      digitalWrite(R,HIGH);
    }  
   
 }
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  //Serial.println("Hello, ESP32!");
  pinMode(R, OUTPUT);
  pinMode(G, OUTPUT);
  pinMode(B, OUTPUT);
  
}

void loop() {
  // put your main code here, to run repeatedly:
   // this speeds up the simulation
  delay(10);
  char x;
  if(x=Serial.read())
   {
     
      
    colorDisplay(x);
     
  }
  }