// constants (or #define with no ; at end of line) won't change. They're used here to set pin numbers:
int redLED = 10;
int greenLED = 9;
int blueLED = 8;
String myColour = "";
String msg="What colour LED? ";

// Variables will change:


void setup() {
  pinMode (redLED, OUTPUT);
  pinMode (greenLED, OUTPUT);
  pinMode (blueLED, OUTPUT);
  Serial.begin(9600);
  }

void loop() {

Serial.println(msg);

while (Serial.available()==0) {
}
myColour=Serial.readStringUntil('\n');
 digitalWrite(greenLED, LOW);
 digitalWrite(redLED, LOW);
 digitalWrite(blueLED, LOW);

Serial.print(Serial.readString());
//Serial.print(myColour);
  
if (myColour=="red" || myColour=="Red"){
  digitalWrite(redLED, HIGH);
  digitalWrite(greenLED, LOW);
  digitalWrite(blueLED, LOW);
  Serial.print(myColour);
  Serial.println(" is lit, others are not.");
  }
else if (myColour=="green" || myColour=="Green"){
     digitalWrite(greenLED, HIGH);
     digitalWrite(redLED, LOW);
    digitalWrite(blueLED, LOW);
    Serial.println("Green is lit, others are not.");
}
else if (myColour=="blue"|| myColour == "Blue"){
  digitalWrite(blueLED, HIGH);
  digitalWrite(greenLED, LOW);
  digitalWrite(redLED, LOW);
  Serial.println("Blue is lit, others are not.");
}
else {

  Serial.print(myColour);
  Serial.print(" is not a valid entry smart arse!");
  Serial.println("");
  }
}