Getting back color of derived panel to change color at Design Time when I click on it?

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Drawing;
using System.Web.UI.Design;
using System.Web.UI.Design.WebControls;
 
 
 
 
namespace AJAXEnabledWebApplication1
{
    [DesignerAttribute(typeof(GPBoxDesigner)),
  ToolboxData("<{0}:GPBox runat=\"server\"></{0}:GPBox>")]
 
    public class GPBox : Panel
    {
        public GPBox()
        {
            this.BorderStyle = BorderStyle.Solid;
            this.BorderWidth = 1;
            this.Width = 300;
            this.Height = 300;
 
            GPBoxDesigner.WasClicked += null;
            GPBoxDesigner.WasClicked += new EventHandler(this.RespondToClick);
        }
 
        private void RespondToClick(object sender, EventArgs e)
        {
 
//////////////////  NOTHING HAPPENS  ///////////////////
            this.BackColor = System.Drawing.Color.Red;
            this.BorderStyle = BorderStyle.Groove;
        }
    }
 
    public class GPBoxDesigner : ControlDesigner
    {
        public static event EventHandler WasClicked;
 
        protected override void OnClick(DesignerRegionMouseEventArgs e)
        {
            base.OnClick(e);
 
            if (WasClicked != null)
            {
                WasClicked(null, null);
            }
            
        }
    }
}