title: Pygame choose color NameError
body: <p>I have a question about pygame. I saw many people can choose their color by just typing the color, like <code>screen.fill(white)</code>. Here is my code:</p>
  <pre><code>import pygame
  pygame.init()
  screen = pygame.display.set_mode((640,480))
  pygame.display.set_caption(&quot;Snake&quot;)
  
  
  gameExit = False
  while not gameExit:
      for event in pygame.event.get():
          if event.type == pygame.QUIT:
              gameExit = True
  
      screen.fill(white)
      pygame.display.update()
  
  
  pygame.quit()
  </code></pre>
  <p>However, I get this error:</p>
  <pre><code> NameError: name 'white' is not defined
  </code></pre>
  <p>Moreover, I remember there is another way to do so, like <code>pygame.COLOR(&quot;white&quot;)</code></p>