[PyGame] Basic Snake game (using OOP)

[Mekire]

Nice work.

A couple criticisms:

• Speed is global, this is unnecessary.
  
• You are constraining your framerate to 10 fps. This is not a great way to slow your program down.
  
• You aren't handling quit events making exiting from the program a little annoying.
  
• Your color constants aren't actually necessary; pygame provides all standard html colors already.
  
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  >>> pg.Color("green")
  (0, 255, 0, 255)
  >>>

• Loop through objects, not indexes. For example, instead of this:
  
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  for i in range(len(snake.square)):
      if snake.square[i].x == apple.x and snake.square[i].y == apple.y:
          apple_xy()

  This:
  
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  for cell in snake.square:
      if cell.x == apple.x and cell.y == apple.y:
          apple_xy() 

• Try to minimize repeated code like this block:
  
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          if event.type == pygame.KEYDOWN:
              if event.key == pygame.K_UP:
                  if y_speed != 1:
                      x_speed = 0
                      y_speed = 0
                      y_speed = -1
                      break
              if event.key == pygame.K_DOWN:
                  if y_speed != -1:
                      x_speed = 0
                      y_speed = 0
                      y_speed = 1
                      break
              if event.key == pygame.K_RIGHT:
                  if x_speed != -1:
                      x_speed = 0
                      y_speed = 0
                      x_speed = 1
                      break
              if event.key == pygame.K_LEFT:
                  if x_speed != 1:
                      x_speed = 0
                      y_speed = 0
                      x_speed = -1
                      break

  Often you can use a dictionary to switch to the correct case in situations like this; the following illustrates the basic idea:
  
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  DIRECT_DICT = {"left" : (-1, 0), "right" : ( 1, 0),
                 "up" : ( 0,-1), "down" : ( 0, 1)}
  
  OPPOSITES = {"left" : "right", "right" : "left",
               "up" : "down", "down" : "up"}
  
  KEY_MAPPING = {(pg.K_LEFT, pg.K_a) : "left", (pg.K_RIGHT, pg.K_d) : "right",
                 (pg.K_UP, pg.K_w) : "up", (pg.K_DOWN, pg.K_s) : "down"}
  
  ## other stuff
  
      def get_key_press(self, key):
          """
          Add directions to the direction queue if key in KEY_MAPPING is pressed.
          """
          for keys in KEY_MAPPING:
              if key in keys:
                  try:
                      self.direction_queue.put(KEY_MAPPING[keys], block=False)
                      break
                  except queue.Full:
                      pass
  
  ## other stuff
  
      def change_direction(self):
          """
          Check direction queue for a new direction.  Directions parallel
          to the snakes current movement are ignored.
          """
          try:
              new = self.direction_queue.get(block=False)
          except queue.Empty:
              new = self.direction
          if new not in (self.direction, OPPOSITES[self.direction]):
              self.vector = DIRECT_DICT[new]
              self.direction = new

Anyway, all that aside great work and good job trying to make everything work in an object oriented manner.
I have a pretty minimal snake game here which has a very basic scene manager if you want to check it out:
https://github.com/Mekire/Snake/blob/master/snake.py