const int RED   = A4;
const int GREEN = A5;
const int BLUE  = A3;

void setup() {
  pinMode(RED,   OUTPUT);
  pinMode(GREEN, OUTPUT);
  pinMode(BLUE,  OUTPUT);
  Serial.begin(9600);
}

void loop() {

  if (Serial.available() > 0) {

    char input = Serial.read();

    if (input == 'R') {
      analogWrite(RED,   0);
      analogWrite(GREEN,   255);
      analogWrite(BLUE,   255);

    }

    if (input == 'Y') {
      analogWrite(RED,   0);
      analogWrite(GREEN,   0);
      analogWrite(BLUE,   255);
    }

    if (input == 'G') {
      analogWrite(RED,   255);
      analogWrite(GREEN,   0);
      analogWrite(BLUE,   255);
    }

    if (input == 'C') {
      analogWrite(RED,   255);
      analogWrite(GREEN,   0);
      analogWrite(BLUE,   0);
    }

    if (input == 'B') {
      analogWrite(RED,   255);
      analogWrite(GREEN,   255);
      analogWrite(BLUE,   0);
    }

    if (input == 'M') {
      analogWrite(RED,   0);
      analogWrite(GREEN,   255);
      analogWrite(BLUE,   0);
    }
    if (input == 'W') {
      analogWrite(RED,   0);
      analogWrite(GREEN,   0);
      analogWrite(BLUE,   0);
    }

    if (input == '0') {
      analogWrite(RED,   255);
      analogWrite(GREEN, 255);
      analogWrite(BLUE,  255);
    }
  
    delay(200);

  }
  
}