title: Can enum parameter be optional in c#?
body: <p>I've used <a href="https://stackoverflow.com/questions/1030090/how-do-you-pass-multiple-enum-values-in-c">this helpful post</a> to learn how to pass a list of Enum values as a parameter.</p>
  
  <p>Now I would like to know whether I can make this parameter optional?</p>
  
  <p>Example:</p>
  
  <pre><code>   public enum EnumColors
      {
          [Flags]
          Red = 1,
          Green = 2,
          Blue = 4,
          Black = 8
      }
  </code></pre>
  
  <p>I want to call my function that receives the Enum param like this:</p>
  
  <pre><code>DoSomethingWithColors(EnumColors.Red | EnumColors.Blue)
  </code></pre>
  
  <p>OR</p>
  
  <pre><code>DoSomethingWithColors()
  </code></pre>
  
  <p>My function should then look like what?</p>
  
  <pre><code>public void DoSomethingWithColors(EnumColors someColors = ??)
   {
    ...
    }
  </code></pre>