rgb windows form

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

namespace arduino_rgb_controller
{
    public partial class Form1 : Form
    {

        bool check1;
        bool check2;
        bool check3;


        public Form1()
        {
            InitializeComponent();
            this.MouseWheel += new System.Windows.Forms.MouseEventHandler(this.Form1_MouseWheel);
        }

        private void Form1_MouseWheel(object sender, MouseEventArgs e)
        {
            if (e.Delta > 0) // On Scroll up mouse wheels.
            {
                if (check1 == true)
                {
                    serialPort1.Open();
                    serialPort1.Write("2");
                    serialPort1.Close();
                }


                if (check2 == true)
                {
                    serialPort1.Open();
                    serialPort1.Write("4");
                    serialPort1.Close();
                }



                if (check3 == true)
                {
                    serialPort1.Open();
                    serialPort1.Write("6");
                    serialPort1.Close();
                }
            }

            else
            {
                if (check1 == true)
                {
                    serialPort1.Open();
                    serialPort1.Write("1");
                    serialPort1.Close();
                }


                if (check2 == true)
                {
                    serialPort1.Open();
                    serialPort1.Write("3");
                    serialPort1.Close();
                }

                if (check3 == true)
                {
                    serialPort1.Open();
                    serialPort1.Write("5");
                    serialPort1.Close();
                }
            }
        }





        private void Form1_Load(object sender, EventArgs e)
        {
            InitializeComponent();
            //the COM port of my Arduino
            serialPort1.PortName = "COM3";
            serialPort1.BaudRate = 9600;
        }



        private void checkBox1_CheckedChanged(object sender, EventArgs e)
        {
           if(check1 == true)
            {
                check1 = false;
            }
           else
            {
                check1 = true;
            }
        }

        private void checkBox2_CheckedChanged(object sender, EventArgs e)
        {
            if (check2 == true)
            {
                check2 = false;
            }
            else
            {
                check2 = true;
            }
        }

        private void checkBox3_CheckedChanged(object sender, EventArgs e)
        {
            if (check3 == true)
            {
                check3 = false;
            }
            else
            {
                check3 = true;
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {

        }

        private void button2_Click(object sender, EventArgs e)
        {

        }

        private void button1_Click_1(object sender, EventArgs e)
        {
            if (check1 == true)
            {
                serialPort1.Open();
                serialPort1.Write("R");
                serialPort1.Close();
            }


            if (check2 == true)
            {
                serialPort1.Open();
                serialPort1.Write("G");
                serialPort1.Close();
            }



            if (check3 == true)
            {
                serialPort1.Open();
                serialPort1.Write("B");
                serialPort1.Close();
            }
        }

        private void button2_Click_1(object sender, EventArgs e)
        {
            if (check1 == true)
            {
                serialPort1.Open();
                serialPort1.Write("r");
                serialPort1.Close();
            }


            if (check2 == true)
            {
                serialPort1.Open();
                serialPort1.Write("g");
                serialPort1.Close();
            }



            if (check3 == true)
            {
                serialPort1.Open();
                serialPort1.Write("b");
                serialPort1.Close();
            }
        }
    }
}