gistfile1.txt

const int greenLEDPin = 9;
const int redLEDPin = 11;
const int blueLEDPin = 10;

void changeLED(int r, int g, int b) {
  analogWrite(greenLEDPin, r);
  analogWrite(redLEDPin,   g);
  analogWrite(blueLEDPin,  b);
}

void setup() {
  Serial.begin(9600);
  
  pinMode(greenLEDPin, OUTPUT);
  pinMode(redLEDPin,   OUTPUT);
  pinMode(blueLEDPin,  OUTPUT);
  
  analogWrite(greenLEDPin, 0);
  analogWrite(redLEDPin,   0);
  analogWrite(blueLEDPin,  0);
}

void loop() {
  const int speed = 1;
    int factor = 1;

    for (int i = 0x000000;; i += factor*speed) {
        //changeLED(b, g, r);
        printf("%x ", i);
        printf("%x %x %x\n", (i & 0xFF0000) >> 16, (i & 0xFF00) >> 8, (i & 0xFF));
        if(i > 3*256){
            factor *= -1;
        }else if(i < 0){
            factor *= -1;
        }
    }
}