code: def test_op_ndoverlay_color_value(self):
      colors = ["blue", "red"]
      overlay = NdOverlay(
          {
              color: Curve(np.arange(i))
              for i, color in enumerate(colors)
          },
          "color",
      ).opts("Curve", color="color")
      plot = mpl_renderer.get_plot(overlay)
      for subplot, color in zip(plot.subplots.values(), colors):
          style = dict(subplot.style[subplot.cyclic_index])
          style = subplot._apply_transforms(
              subplot.current_frame, {}, style
          )
          self.assertEqual(style["color"], color)
  
imports: import datetime
  import numpy
  import pandas
  import pytest
  from holoviews.core.options import AbbreviatedException
  from holoviews.core.overlay import NdOverlay
  from holoviews.element import Curve
  from holoviews.util.transform import dim
  from .test_plot import TestMPLPlot, mpl_renderer
label_desc: Use image node_id 17 for calling the TestCurvePlot obj's underlying member method code with example usage: obj.test_op_ndoverlay_color_value() without return types