def contains_background_colors(self):
        """ Return true if any background color is set other than black or default """
        for frame in self.frames:
            for line in frame.newColorMap:
                for pair in line:
                    if pair[1] > 0:
                        return True
        return False
 Return true if any background color is set other than black or default 
durdraw/durdraw_movie.py