как правильно реализовать данную программу через семафор?

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Threading;

namespace lablab
{
    class Program
    {
        public static Thread thrd_red, thrd_yellow, thrd_green;
        public static bool r1 = false;
        public static bool r2 = false;
        public static bool r3 = false;
        public static void red()
        {
            Thread.Sleep(100);
            while (true)
            {

                Console.WriteLine("red");
                Thread.Sleep(2500);
                thrd_yellow.Resume();
                thrd_red.Suspend();
            }
        }
        public static void yellow()
        {
            while (true)
            {

                Console.WriteLine("yellow");
                Thread.Sleep(1500);
                thrd_green.Resume();
                thrd_yellow.Suspend();
            }
        }
        public static void green()
        {
            while (true)
            {

                Console.WriteLine("green");
                Thread.Sleep(500);
                thrd_red.Resume();
                thrd_green.Suspend();
            }
        }
        static void Main(string[] args)
        {
            thrd_red = new Thread(red);
            thrd_yellow = new Thread(yellow);
            thrd_green = new Thread(green);


            thrd_red.Start();
            thrd_yellow.Start();
            thrd_yellow.Suspend();
            thrd_green.Start();
            thrd_green.Suspend();

            thrd_red.Join();
            thrd_yellow.Join();
            thrd_green.Join();

        }
    }
}