using System;

using Newtonsoft.Json;

using System.Drawing;

public class Program

{

    public class Test

    {

        public Color normalColor;

        public object objectType;

    }

    public static void Main()

    {

        Test test = new Test();

        test.normalColor = Color.Green;

        test.objectType = Color.Green;

        Console.WriteLine(JsonConvert.DeserializeObject<Test>(JsonConvert.SerializeObject(test)).normalColor.GetType());

        Console.WriteLine(JsonConvert.DeserializeObject<Test>(JsonConvert.SerializeObject(test)).objectType.GetType());

    }

}

​

public class Container

{

    public System.Drawing.Color Color { get; set; }

}