code: def test_colorDistance():
      pg.colorDistance(
          [pg.Qt.QtGui.QColor(0, 0, 0), pg.Qt.QtGui.QColor(255, 0, 0)]
      )
      pg.colorDistance([])
  
imports: from collections import OrderedDict
  from copy import deepcopy
  import numpy
  import pytest
  from numpy.testing import assert_array_almost_equal
  import pyqtgraph
  from pyqtgraph.functions import arrayToQPath, eq
  from pyqtgraph.Qt import QtGui
label_desc: Use image node_id 14 for calling a global function with example usage: test_colorDistance() without return types