int redPin=9;
int greenPin=10;
int bluePin=11;
String myColor;
String msg="What color you want?";
int dt=10000;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.println(msg);
  while (Serial.available()==0){

  }
  myColor=Serial.readString();
  Serial.println(myColor);
  if (myColor=="red"){
    digitalWrite(9, HIGH);
    delay(dt);
    digitalWrite(10, LOW);
    digitalWrite(11, LOW);
    delay(dt);
  }
  if (myColor=="green"){
    digitalWrite(9, LOW);
    digitalWrite(10, HIGH);
    digitalWrite(11, LOW);
    delay(dt);
  }
  if (myColor=="blue"){
    digitalWrite(9, LOW);
    digitalWrite(10, LOW);
    digitalWrite(11, HIGH);
    delay(dt);
  }
}