static SS parseColonProperties_withMultiLines(S text) {
  ret parseColonProperties_withMultiLines(text, new LinkedHashMap);
}

static SS parseColonProperties_withMultiLines(S text, SS map) {
  LS lines = lines(text);
  int n = l(lines);
  for iLine to n: {
    S s = trim(lines.get(iLine));
    int i = indexOf(s, ':');
    if (i > 0) {
      if (endsWith(s, ':')) {
        S key = trim(dropLast(s));
        int j = iLine+1;
        while (j < n && emptyAfterTrim(lines.get(j))) ++j;
        int k = j;
        while (j < n && !emptyAfterTrim(lines.get(j))) ++j;
        map.put(key, joinLines(subList(lines, k, j)));
        iLine = j;
      } else
        map.put(trimSubstring(s, 0, i), trimSubstring(s, i+1));
    }
  }
  ret map;
}

Began life as a copy of #1020412