// returns pairs (col332 [0-255], percentage of image)
static LPair<Int, Double> dominant332colorsWithPercentage(RGBImage img) {
  int[] array = histogram332_array(img);
  new MultiSet<Int> ms;
  int total = 0;
  for i over array: {
    int x = array[i];
    ms.add(i, x); 
    total += x;
  }
  double total2 = total /= 100;
  ret map(ms.highestFirst(), col -> pair(col, doubleRatio(ms.get(col), total2)));
}

static LPair<Int, Double> dominant332colorsWithPercentage(BufferedImage img) {
  ret dominant332colorsWithPercentage(RGBImage(img));
}