const int redPin = 11;
const int bluePin = 10;
const int greenPin = 9;

int val;

void setup() {
   pinMode(redPin, OUTPUT);
   pinMode(bluePin, OUTPUT);
   pinMode(greenPin, OUTPUT);
   Serial.begin(9600);
}

void loop() {
   for (val = 0; val < 255; val ++) {
      analogWrite(redPin, val);
      analogWrite(bluePin, 255 - val);
      analogWrite(greenPin, 128 - val);
      Serial.println(val);
      delay(1);
   }
}