title: can't communicate between classes using delegations
body: <p>I have model class which has color parameter, and view class which also has UIColor. Using delegations how can I change my view color, when it changes in model.</p>
  
  <pre><code>//Model.h
  
  @class Ball;
  @protocol BallDelegate &lt;NSObject&gt;
  
  -(void)ball:(Ball*)ball wasColorChanged;
  
  @end
  
  @interface Ball : NSObject
  
  @property UIColor* color;
  @property (weak) id &lt;BallDelegate&gt; delegate;
  
  @end
  </code></pre>
  
  <p>Now, how can I pass the value to my view, how to invoke that.</p>