new_contents: from collections import OrderedDict
  
  
  class Pallete(OrderedDict):
      def to_normalized_rgb(self):
          for value in self:
              nr = self[value][0] / 255.0
              ng = self[value][1] / 255.0
              nb = self[value][2] / 255.0
  
              yield nr, ng, nb
  
  
  # http://www.nature.com/nmeth/journal/v8/n6/full/nmeth.1618.html
  seven_colors = Pallete([
      ('blue', (0, 114, 178)),
      ('orange', (230, 159, 0)),
      ('blueish_green', (0, 158, 115)),
      ('vermillion', (213, 94, 0)),
      ('sky_blue', (86, 180, 233)),
      ('yellow', (240, 228, 66)),
      ('reddish_purple', (204, 121, 167))
  ])
  
subject: add colorblind friendly palette