code: def test_hist_color_single_band(basic_image):
      """Check that the color argument works for single bands."""
      f, ax = ep.hist(basic_image, colors=["red"])
      facecolor = ax.patches[0].__dict__.get("_original_facecolor")
      assert np.array_equal(facecolor, np.array([1.0, 0.0, 0.0, 1.0]))
      plt.close(f)
  
imports: import numpy
  import pytest
  import matplotlib.pyplot
  import earthpy.plot
label_desc: Use image node_id 9 for calling a global function with example usage: test_hist_color_single_band(basic_image) without return types