// returns pairs (color name, percentage of image)
static LPair<S, Double> dominant332webColorNamesWithPercentage(RGBImage img) {
  new Map<S, Double> map;
  for (Pair<Int, Double> p : dominant332colorsWithPercentage(img)) {
    S col = webColorNameFrom332(p.a);
    map.put(col, or(map.get(col), 0.0) + p.b);
  }
  ret sortByPairBDesc(mapToPairs(map));
}

static LPair<S, Double> dominant332webColorNamesWithPercentage(BufferedImage img) {
  ret dominant332webColorNamesWithPercentage(RGBImage(img));
}