#define NUMELEMENTS(x) (sizeof(x) / sizeof(x[0]))

struct COLOR {
  String name;
  int red;
  int green;
  int blue;
};

COLOR colors[] = {
  {"red", 255, 0, 0},
  {"green", 0, 255, 0},
  {"blue", 0, 0, 255},
  {"off", 0, 0, 0},
  {"yellow", 255, 255, 0},
  {"cyan", 92, 255, 255},
  { "magneta", 255, 0, 255},
  {"aqua", 0, 255, 255}
};

byte redPin = 11;
byte greenPin = 10;
byte bluePin = 9;

String myColor;
bool found = false;

void setup() {
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);
  Serial.begin(115200);
}

void loop() {
  Serial.println("Which colour do you want to see?");

  // Wait until user input is available
  while (Serial.available() == 0) {}

  myColor = Serial.readString();

  for (uint8_t cnt = 0; cnt < NUMELEMENTS(colors) ; cnt++) {
    if (colors[cnt].name == myColor) {
      showLeds(colors[cnt].red, colors[cnt].green, colors[cnt].blue);
      found = true;
      break;
    }
  }

  if (!found) {
    Serial.println("");
    Serial.println("I do not know that color");
    Serial.println("");
    showLeds(0, 0, 0);
  } else {
    found = false;
  }
}

void showLeds(int red, int green, int blue) {
  analogWrite(redPin, red);
  analogWrite(bluePin, blue);
  analogWrite(greenPin, green);
}