how to change my border in menustrip

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C#

my problem is : i made a menu like (File) and come from it many items like (New-Edit-,,,) when i change the color the background color to be by example Red the items won't change the color so i change the back color of every item but it have a white border also and this is my code

public partial class Start_Page : Form
    {
        public Start_Page()
        {
            InitializeComponent();
            menuStrip1.Renderer = new MyRenderer();



        }

        private class MyRenderer : ToolStripProfessionalRenderer
        {
            public MyRenderer() : base(new MyColors()) { }
        }

        private class MyColors : ProfessionalColorTable
        {
            public override Color MenuItemSelected
            {
                get { return Color.FromArgb(11, 126, 222); }
            }
            public override Color MenuItemSelectedGradientBegin
            {
                get { return Color.FromArgb(11, 126, 222); }
            }
            public override Color MenuItemSelectedGradientEnd
            {
                get { return Color.FromArgb(11, 126, 222); }
            }
            public override Color MenuItemPressedGradientBegin
            {
                get{ return Color.FromArgb(8, 64, 101); }
            }
            public override Color MenuItemPressedGradientEnd
            {
                get { return Color.FromArgb(8, 64, 101); }
            }
            public override Color MenuBorder
            {
                get
                {
                    return Color.Blue;
                }
            }
            public override Color MenuItemBorder
            {
                get
                {
                    return Color.Blue;
                }
            }

the border have the blue color but the white color still there how i clear it ??