'Returns the approximate CIE 1931 x,y coordinates represented by the
supplied hexColor parameter, or of a random color if the parameter
is not passed.'

def getCIEColor(self, hexColor=None):

    xy = []
    if hexColor:
        xy = self.hexToCIE1931(hexColor)
    else:
        r = self.color.randomRGBValue()
        g = self.color.randomRGBValue()
        b = self.color.randomRGBValue()
        xy = self.rgbToCIE1931(r, g, b)
    return xy
