docs: def get_known_name(s: str) -> Optional[Tuple[str, ColorArg]]:
      """ Reverse translate a terminal code to a known color name, if possible.
          Returns a tuple of (codetype, knownname) on success.
          Returns None on failure.
      """
  
      if not s.endswith('m'):
          # All codes end with 'm', so...
          return None
      if s.startswith('\033[38;5;'):
          # Extended fore.
          name = codes_reverse['fore'].get(s, None)
          if name is None:
              num = get_code_num(s)
              return ('extended fore', num)
          else:
              return ('extended fore', name)
      elif s.startswith('\033[48;5;'):
          # Extended back.
          name = codes_reverse['back'].get(s, None)
          if name is None:
              num = get_code_num(s)
              return ('extended back', num)
          else:
              return ('extended back', name)
      elif s.startswith('\033[38;2'):
          # RGB fore.
          vals = get_code_num_rgb(s)
          if vals is not None:
              return ('rgb fore', vals)
      elif s.startswith('\033[48;2'):
          # RGB back.
          vals = get_code_num_rgb(s)
          if vals is not None:
              return ('rgb back', vals)
      elif s.startswith('\033['):
          # Fore, back, style.
          number = get_code_num(s)
          # Get code type based on number.
          if (number <= 7) or (number == 22):
              codetype = 'style'
          elif (((number >= 30) and (number < 40)) or
                  ((number >= 90) and (number < 100))):
              codetype = 'fore'
          elif (((number >= 40) and (number < 50)) or
                  ((number >= 100) and (number < 110))):
              codetype = 'back'
          else:
              raise InvalidEscapeCode(
                  number,
                  'Expecting 0-7, 22, 30-39, or 40-49 for escape code',
              )
  
          name = codes_reverse[codetype].get(s, None)
          if name is not None:
              return (codetype, name)
  
      # Not a known escape code.
      return None