Easy code snippet broken

Try like this:

using System;

namespace MyApplication
{
	class Program
	{
		static void Main(string[] args)
		{
				Car myObj = new Car();
				Console.WriteLine(myObj.color);
				Console.WriteLine(myObj.maxSpeed);
		}

		public class Car
		{
			public string color = "red";
			public int maxSpeed = 200;
		}
	}
}

It's also possible to put the Car class outside the Program class:

class Car
{
    public string color = "red";
    public int maxSpeed = 200;
}

In fact it is recommended to put each class in it's own file, but for such a small example it is not necessary.
Note that the use of Access modifiers like Public for a class differs when using a Console or Winforms application, the Console application sometimes does not like it.