Converting Bitmap to Icon

I'm trying to convert an image from a Bitmap to a Windows icon. This is the code.

private void btnCnvrtSave_Click(object sender, EventArgs e)
{
    Bitmap bmp = (Bitmap)picturePanel.BackgroundImage;
    Bitmap newBmp = new Bitmap(bmp);
    Bitmap targetBmp = newBmp.Clone(new Rectangle(0, 0, newBmp.Width, newBmp.Height), PixelFormat.Format64bppArgb);
    IntPtr Hicon = targetBmp.GetHicon();
    Icon myIcon = Icon.FromHandle(Hicon);

    SaveFileDialog sfd = new SaveFileDialog();
    sfd.Title = "Save Icon";
    sfd.Filter = "Icon|*.ico";
    sfd.ShowDialog();

    FileStream fileStream = new FileStream(sfd.FileName,FileMode.OpenOrCreate);
    myIcon.Save(fileStream);
    fileStream.Flush();
    fileStream.Close();

    MessageBox.Show("Image is converted successfully!");
}

The code is working fine but the problem is, when I convert the picture to an icon the converted icon loses its true colors and gradients (shown in image). So, is there any way by which I can convert the image without losing its colors?

This is what my icon looks like.