This is an example on how to use a toolstrip render. This example shows by making a ToolStripButton object non-clickable by changing the background colors to match the system colors in every case.

Renderers.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace CustomRenders
{
    /// <summary>
    /// Provides an alternate way of painting toolstrip objects
    /// 
    /// https://docs.microsoft.com/en-us/dotnet/api/system.windows.forms.toolstripsystemrenderer?view=netframework-4.8
    /// </summary>
    class Renderers : ToolStripProfessionalRenderer
    {
        /// <summary>
        /// Overrides OnRendererButtonBackground
        /// 
        /// https://docs.microsoft.com/en-us/dotnet/api/system.windows.forms.toolstripsystemrenderer.onrenderbuttonbackground?view=netframework-4.8
        /// </summary>
        /// <param name="e"></param>
        protected override void OnRenderButtonBackground(ToolStripItemRenderEventArgs e)
        {
            if (!e.Item.Selected)
            {
                base.OnRenderButtonBackground(e);
            }
            else
            {
                switch (e.Item.Name)
                {
                    case "toolStripButton1": // This makes the button non-clickable
                        Rectangle rectangle = new Rectangle(0, 0, e.Item.Size.Width - 1, e.Item.Size.Height - 1);
                        e.Graphics.FillRectangle(SystemBrushes.Control, rectangle);
                        e.Graphics.DrawRectangle(SystemPens.Control, rectangle);
                        break;
                    default:
                        base.OnRenderButtonBackground(e);
                        break;
                }
            }
                       
        }
    }
}