title: How to remove an item for a OR'd enum?
body: <p>I have an enum like:</p>
  
  <pre><code>public enum Blah
  {
      RED = 2,
      BLUE = 4,
      GREEN = 8,
      YELLOW = 16
  }
  
  Blah colors = Blah.RED | Blah.BLUE | Blah.YELLOW;
  </code></pre>
  
  <p>How could I remove the color blue from the variable colors?</p>