code: def test_icon_invalid_marker_colors():
      pytest.warns(UserWarning, Icon, color="lila")
      pytest.warns(UserWarning, Icon, color=42)
      pytest.warns(UserWarning, Icon, color=None)
  
imports: import warnings
  import numpy
  import pytest
  from folium import GeoJson, Map, TileLayer
  from folium.map import CustomPane, Icon, LayerControl, Marker, Popup
  from folium.utilities import normalize
label_desc: Use image node_id 16 for calling a global function with example usage: test_icon_invalid_marker_colors() without return types