How to group Enum values?
<p>How can I group Enum values?<br>
Assume I have an enum like</p>

<pre><code>public enum Colors
  {
    LightBlue,
    LightGreen,
    DarkGreen,
    Black,
    White,
    LightGry,
    Yellow
  }
</code></pre>

<p>Now I want to define some groups of colors, e.g. the light colors (LightBlue, LightGreen, White, LightGray, Yellow) and dark colors (Black, DarkGreen).<br>
So I can ask for groups at different places in my code.<br>
If I remember correctly my Java time I just could add methods to the enums in Java. I think that is not possible in C#. But maybe there are other ways.</p>

<p>Edit1: Of course I can add a Utility class with static member like <code>IsADarkColor(Colors c)</code>. But I would like do it without an additional class because I could forget that related class when I need that feature.</p>
