const int rgbPins[] = { 11, 10, 9};
#define LDR 18
void setup() {
  pinMode(LDR, INPUT);
}

void loop() {
 if (digitalRead(LDR) == LOW)
    {
      analogWrite(27,LOW);
    }
     else
    { 
     analogWrite(27,HIGH);
    }
  }