code: def test_label_color_op_update(self):
      labels = HoloMap(
          {
              0: Labels(
                  [
                      (0, 0, "#000000"),
                      (0, 1, "#FF0000"),
                      (0, 2, "#00FF00"),
                  ],
                  vdims="color",
              ),
              1: Labels(
                  [
                      (0, 0, "#FF0000"),
                      (0, 1, "#00FF00"),
                      (0, 2, "#0000FF"),
                  ],
                  vdims="color",
              ),
          }
      ).opts(color="color")
      plot = mpl_renderer.get_plot(labels)
      artist = plot.handles["artist"]
      self.assertEqual(
          [a.get_color() for a in artist],
          ["#000000", "#FF0000", "#00FF00"],
      )
      plot.update((1,))
      artist = plot.handles["artist"]
      self.assertEqual(
          [a.get_color() for a in artist],
          ["#FF0000", "#00FF00", "#0000FF"],
      )
  
imports: import numpy
  from holoviews.core.dimension import Dimension
  from holoviews.core.options import Cycle
  from holoviews.core.spaces import HoloMap
  from holoviews.element import Labels
  from holoviews.plotting.util import rgb2hex
  from .test_plot import TestMPLPlot, mpl_renderer
label_desc: Use image node_id 7 for calling the TestLabelsPlot obj's underlying member method code with example usage: obj.test_label_color_op_update() without return types