int lowFreqValue = 0;
int midFreqValue = 0;
int highFreqValue = 0;
int redValue = 0;
int greenValue = 0;
int blueValue = 0;

void setup() {
  pinMode(13, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(11, OUTPUT);
}

void loop() {
  lowFreqValue = analogRead(A0);
  midFreqValue = analogRead(A1);
  highFreqValue = analogRead(A2);
  redValue = lowFreqValue >> 2;
  greenValue = midFreqValue >> 2;
  blueValue = highFreqValue >> 2;
  analogWrite(13, redValue);
  analogWrite(12, greenValue);
  analogWrite(11, blueValue);
  delay(10);
}