docs: def _hex_to_rgb(hex_code):
      """
      >>> _hex_to_rgb("007fff")
      (0, 127, 255)
      """
      if len(hex_code) != 6:
          raise ValueError(hex_code + " is not a string of length 6, cannot convert to rgb.")
      return tuple(map(ord, hex_code.decode("hex")))