title: invalid color argument for pygame
body: <p>I created this class:</p>
  
  <pre><code>class randcolour:
      def __init__(self):
          self.r = random.randint(0,255)
          self.g = random.randint(0,255)
          self.b = random.randint(0,255)
      def return_colour(self):
          return (self.r, self.g, self.b)
  colour = randcolour()
  colour.return_colour()
  </code></pre>
  
  <p>When I try to use it in </p>
  
  <pre><code>pygame.draw.rect(screen,colour,[btnx,btny,btnwi,btnle])
  </code></pre>
  
  <p>I get this error:</p>
  
  <pre><code>TypeError: invalid color argument
  </code></pre>
  
  <p>What is wrong here?</p>