public ClrPreview(System.Drawing.Color startColor, System.Windows.Forms.Control parent) { if (instance == null) { instance = this; this.parent = parent; InitializeComponent(); WindowStartupLocation = WindowStartupLocation.Manual; PreviewMouseDoubleClick += ClrPreview_PreviewMouseDoubleClick; PreviewMouseLeftButtonDown += OnMouseDown; PreviewMouseUp += OnMouseUp; Loaded += (snd, evt) => { UpdateLoc(); UpdateColor(startColor.ConvertColor()); }; Closed += (s, e) => instance = null; } }