C# - Die Farbe eines Pixels in einer Windows Form abfragen

private Color GetPixelAtPoint(System.Windows.Forms.Control Ctrl, System.Drawing.Point Location)
{
    Bitmap TmpImg = new Bitmap(Ctrl.ClientSize.Width, Ctrl.ClientSize.Height);            
    Ctrl.DrawToBitmap(TmpImg, Ctrl.ClientRectangle);
    return TmpImg.GetPixel(Location.X, Location.Y);
}