code: def validate_color_for_prop_cycle(s):
      # Special-case the N-th color cycle syntax, this obviously can not
      # go in the color cycle.
      if isinstance(s, bytes):
          match = re.match(b"^C[0-9]$", s)
          if match is not None:
              raise ValueError(
                  "Can not put cycle reference ({cn!r}) in "
                  "prop_cycler".format(cn=s)
              )
      elif isinstance(s, six.string_types):
          match = re.match("^C[0-9]$", s)
          if match is not None:
              raise ValueError(
                  "Can not put cycle reference ({cn!r}) in "
                  "prop_cycler".format(cn=s)
              )
      return validate_color(s)
  
imports: from __future__ import absolute_import, division, print_function
  import six
  from functools import reduce
  import operator
  import os
  import warnings
  import re
  from matplotlib import cbook, testing
  from matplotlib.cbook import mplDeprecation, deprecated, ls_mapper
  from matplotlib.fontconfig_pattern import parse_fontconfig_pattern
  from matplotlib.colors import is_color_like
  from cycler import Cycler, cycler
label_desc: Use image node_id 21 for calling a global function with example usage: validate_color_for_prop_cycle(s) and returns: validate_color