title: Kivy make button in grid blink
body: <p>I've tried multiple different solutions for this and I'm out of idea's. I'm brand new to Kivy and still learning. I'm building a very basic memorization game. I need the buttons inside the grid to blink in a certain order. I'm confident that I can make that work, however I can't figure out how to get one of the buttons to blink. Can anyone point me in the right direction? I know I just need need it to change colors for a second and then change back.</p>
  
  <pre><code>from kivy.app import App
  from kivy.clock import Clock
  from kivy.uix.button import Button
  from kivy.uix.widget import Widget
  from kivy.uix.gridlayout import GridLayout
  from random import random
  import time
  
  
  class MemorizeGame(GridLayout):
      def __init__(self, **kwargs):
          super(MemorizeLayout, self).__init__(**kwargs)
          self.cols = 2
  
          #create buttons
          self.button1 = Button(text='', background_color=(0,0,1,1))
          self.button2 = Button(text='', background_color=(0,1,1,1))
          self.button3 = Button(text='', background_color=(1,0,1,1))
          self.button4 = Button(text='', background_color=(0,1,0,1))
          self.buttonList = [self.button1, self.button2, self.button3, self.button4]
  
          #add buttons to the screen
          for button in self.buttonList:
              self.add_widget(button)
  
      def blinkSquare(self):
          #logic to make a square blink
  
  class MemorizeApp(App):
  
      def build(self):
          game= MemorizeGame()
          return game
  
  if __name__ == "__main__":
      MemorizeApp().run()
  </code></pre>