C# Shaded Ellipse Control Class

Ellipse.cs

public class Ellipse : Control
    {
        private readonly IContainer components = null;
        private Color _centerreflectioncolor = Color.FromArgb(180, 135, 206, 250);
        private Color _color = Color.DodgerBlue;
        private Color _lightColor, _darkColor, _darkDarkColor;
        private bool _on = true;
        private bool _reflectionon = true;
        private readonly Color[] _surroundcolors = {Color.FromArgb(0, 135, 206, 250)};
        public Ellipse()
        {
            InitializeComponent();
            SetStyle(ControlStyles.DoubleBuffer
                     | ControlStyles.AllPaintingInWmPaint
                     | ControlStyles.ResizeRedraw
                     | ControlStyles.UserPaint
                     | ControlStyles.SupportsTransparentBackColor, true);
        }
        [DefaultValue(typeof(Color), "30, 144, 255")]
        public Color Color
        {
            get => _color;
            set
            {
                _color = value;
                _lightColor = ControlPaint.Light(value, .4f);
                _darkColor = ControlPaint.Dark(_lightColor, .2f);
                _darkDarkColor = ControlPaint.DarkDark(_lightColor);
                Invalidate();
            }
        }
        [DefaultValue(typeof(Color), "180, 135, 206, 250")]
        public Color ReflectionColor
        {
            get => _centerreflectioncolor;
            set
            {
                _centerreflectioncolor = value;
                Invalidate();
            }
        }
        [DefaultValue(typeof(bool), "true")]
        public bool On
        {
            get => _on;
            set
            {
                _on = value;
                Invalidate();
            }
        }
        [DefaultValue(typeof(bool), "true")]
        public bool ReflectionOn
        {
            get => _reflectionon;
            set
            {
                _reflectionon = value;
                Invalidate();
            }
        }
        protected override void OnPaint(PaintEventArgs e)
        {
            var offScreenBmp = new Bitmap(ClientRectangle.Width, ClientRectangle.Height);
            using (var g = Graphics.FromImage(offScreenBmp))
            {
                g.SmoothingMode = SmoothingMode.HighQuality;
                DrawControl(g, On);
                e.Graphics.DrawImageUnscaled(offScreenBmp, 0, 0);
            }
        }
        private void DrawControl(Graphics g, bool on)
        {
            var lightColor = on ? _color : Color.FromArgb(180, _darkColor);
            var darkColor = on ? _darkColor : _darkDarkColor;
            var width = Width - (Padding.Left + Padding.Right);
            var height = Height - (Padding.Top + Padding.Bottom);
            var diameter = Math.Min(width, height);
            diameter = Math.Max(diameter - 1, 1);
            var rectangle = new Rectangle(Padding.Left, Padding.Top, diameter, diameter);
            g.FillEllipse(new SolidBrush(darkColor), rectangle);
            var path = new GraphicsPath();
            path.AddEllipse(rectangle);
            var pathBrush = new PathGradientBrush(path)
            {
                CenterColor = lightColor,
                SurroundColors = new[] {Color.FromArgb(0, lightColor)}
            };
            g.FillEllipse(pathBrush, rectangle);
            if (_reflectionon)
            {
                var offset = Convert.ToInt32(diameter * .15F);
                var diameter1 = Convert.ToInt32(rectangle.Width * .8F);
                var whiteRect = new Rectangle(rectangle.X - offset, rectangle.Y - offset, diameter1, diameter1);
                var path1 = new GraphicsPath();
                path1.AddEllipse(whiteRect);
                var pathBrush1 = new PathGradientBrush(path)
                {
                    CenterColor = _centerreflectioncolor,
                    SurroundColors = _surroundcolors
                };
                g.FillEllipse(pathBrush1, whiteRect);
            }

            g.SetClip(ClientRectangle);
            if (On) g.DrawEllipse(new Pen(Color.FromArgb(85, Color.Black), 1F), rectangle);
        }
        protected override void Dispose(bool disposing)
        {
            if (disposing)
                components?.Dispose();
            base.Dispose(disposing);
        }
        private void InitializeComponent()
        {
            SuspendLayout();
            Name = "Ellipse";
            Size = new Size(10, 10);
            _lightColor = ControlPaint.Light(Color.DodgerBlue, .4f);
            _darkColor = ControlPaint.Dark(_lightColor, .2f);
            _darkDarkColor = ControlPaint.DarkDark(_lightColor);
            ResumeLayout(false);
        }
    }