using System;

public class Program

{

    enum Colors : short {

        None = 0,

        Red = 1,

        Blue = 2,

        Green = 4,

    }

    public static void Main()

    {

        var color = Colors.None;

        Console.WriteLine("{0} red {1} blue {2} green {3}", color, color.HasFlag(Colors.Red), color.HasFlag(Colors.Blue), color.HasFlag(Colors.Green));

        color |= Colors.Red;

        Console.WriteLine("{0} red {1} blue {2} green {3}", color, color.HasFlag(Colors.Red), color.HasFlag(Colors.Blue), color.HasFlag(Colors.Green));

        color |= Colors.Blue;

        Console.WriteLine("{0} red {1} blue {2} green {3}", color, color.HasFlag(Colors.Red), color.HasFlag(Colors.Blue), color.HasFlag(Colors.Green));

        color |= Colors.Green;

        Console.WriteLine("{0} red {1} blue {2} green {3}", color, color.HasFlag(Colors.Red), color.HasFlag(Colors.Blue), color.HasFlag(Colors.Green));

    }

}