Convert a String with Minecraft color codes (http://minecraft.gamepedia.com/Formatting_codes) to its html representation using <font color=...

ColorChanger4Minecraft.java

private ArrayList<Pair<Integer, Character>> getColorCodes() {
  ArrayList<Pair<Integer, Character>> colorCodes = new ArrayList<>();
  
  colorCodes.add(new Pair<>(0x000000, '0'));
  colorCodes.add(new Pair<>(0x0000AA, '1'));
  colorCodes.add(new Pair<>(0x00AA00, '2'));
  colorCodes.add(new Pair<>(0x00AAAA, '3'));
  colorCodes.add(new Pair<>(0xAA0000, '4'));
  colorCodes.add(new Pair<>(0xAA00AA, '5'));
  colorCodes.add(new Pair<>(0xFFAA00, '6'));
  colorCodes.add(new Pair<>(0xAAAAAA, '7'));
  colorCodes.add(new Pair<>(0x555555, '8'));
  colorCodes.add(new Pair<>(0x5555FF, '9'));
  colorCodes.add(new Pair<>(0x55FF55, 'a'));
  colorCodes.add(new Pair<>(0x55FFFF, 'b'));
  colorCodes.add(new Pair<>(0xFF5555, 'c'));
  colorCodes.add(new Pair<>(0xFF55FF, 'd'));
  colorCodes.add(new Pair<>(0xFFFF55, 'e'));
  colorCodes.add(new Pair<>(0xFFFFFF, 'f'));

  return colorCodes;
}

private CharSequence toHtml(String s) {
  // replace all \u00A7 color codes with their hex representation
  for (Pair<Integer, Character> colorCode : getColorCodes()) {
      s = s.replace("\u00A7" + colorCode.second, "</font><font color=\"" + colorCode.first + "\">");
  }

  return Html.fromHtml("<font>" + s + "</font>");
}

Note that this will only work on android because some android only classes are used (android.text.Html and android.util.Pair)