code: def rainbow(n=1000, saturation=1, value=1):
      
      for i in range(n):
          hue = i / float(n)
          color = [int(x * 255) for x in colorsys.hsv_to_rgb(hue, saturation, value)]
          yield ("#%02x%02x%02x" % tuple(color)).upper()
docs: A generator that yields 'n' hues from the rainbow in the hex format #RRGGBB.
      By default the saturation and value (from HSV) are both set to 1.