code: def validate_color_for_prop_cycle(s):
      # N-th color cycle syntax can't go into the color cycle.
      if isinstance(s, str) and re.match("^C[0-9]$", s):
          raise ValueError(
              f"Cannot put cycle reference ({s!r}) in prop_cycler"
          )
      return validate_color(s)
  
imports: import ast
  from functools import lru_cache, reduce
  from numbers import Real
  import operator
  import os
  import re
  import numpy
  from matplotlib import _api, cbook
  from matplotlib.cbook import ls_mapper
  from matplotlib.colors import Colormap, is_color_like
  from matplotlib._fontconfig_pattern import parse_fontconfig_pattern
  from matplotlib._enums import JoinStyle, CapStyle
  from cycler import Cycler, cycler
label_desc: Use image node_id 15 for calling a global function with example usage: validate_color_for_prop_cycle(s) and returns: validate_color