code: def test_yellow():
      assert Color("cmyk(0, 0, 100%, 0)").yellow == 1
      assert Color("cmyk(0, 0, 0, 0)").yellow == 0
      c = Color("none")
      c.yellow = 1
      assert c.yellow == 1
  
imports: import ctypes
  import time
  import warnings
  from pytest import mark, raises
  from wand.color import Color
  from wand.compat import xrange
  from wand.version import QUANTUM_DEPTH, MAGICK_VERSION_INFO
label_desc: Use image node_id 13 for calling a global function with example usage: test_yellow() without return types