using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public static void Main(string[] args)

    {

        var strategies = new Dictionary<string, IStrategy>

        {

            ["default"] = new DefaultColor(),

            ["green"] = new GreenColor(),

            ["cyan"] = new CyanColor()

        };

        args = args ?? new string[] { "default" };

        var strategyKey = args[0];

        if (!strategies.ContainsKey(strategyKey))

            strategyKey = "default";

        var text = "This will be printed in {0} color.";

        strategies[strategyKey].Execute();

        Console.WriteLine(text, args[0]);

    }

}

​

public interface IStrategy

{

    void Execute();

}

​

public sealed class DefaultColor : IStrategy

{

    public void Execute()

    {

        // This breaks in dotnetfiddle

        //Console.ForegroundColor = ConsoleColor.Gray;

        Console.WriteLine("Set to default console color.");

    }

}

​

public sealed class CyanColor : IStrategy

{

    public void Execute()

    {

        // This breaks in dotnetfiddle

        //Console.ForegroundColor = ConsoleColor.Cyan;

        Console.WriteLine("Cyan is pretty, if you're an idiot.");

    }

}

​

public sealed class GreenColor : IStrategy

{

    public void Execute()

    {

        // This breaks in dotnetfiddle

        //Console.ForegroundColor = ConsoleColor.Green;

        Console.WriteLine("Ah, green. A classic.");

    }

}