code: def test_vectorfield_color_op(self):
      vectorfield = VectorField(
          [
              (0, 0, 0, 1, "#000000"),
              (0, 1, 0, 1, "#FF0000"),
              (0, 2, 0, 1, "#00FF00"),
          ],
          vdims=["A", "M", "color"],
      ).opts(color="color")
      plot = mpl_renderer.get_plot(vectorfield)
      artist = plot.handles["artist"]
      self.assertEqual(
          artist.get_facecolors(),
          np.array([[0, 0, 0, 1], [1, 0, 0, 1], [0, 1, 0, 1]]),
      )
  
file_path: holoviews/holoviews/tests/plotting/matplotlib/test_vectorfieldplot.py
imports: import numpy
  import pytest
  from holoviews.core.options import AbbreviatedException
  from holoviews.core.spaces import HoloMap
  from holoviews.element import VectorField
  from ..utils import ParamLogStream
  from .test_plot import TestMPLPlot, mpl_renderer
label_desc: Use image node_id 1 for calling the TestVectorFieldPlot obj's underlying member method code with example usage: obj.test_vectorfield_color_op() without return types