new_contents: 
  class Color(object):
      def __init__(self, *args):
          if len(args) == 4:
              r, g, b, a = args
          else:
              raise NotImplementedError("implement me")
          self.r = r
          self.g = g
          self.b = b
          self.a = a
  
subject: Make blitting work (the basics anyway)