how to change color programmatically?

if (IsConnectLine != true)
                    {
                        int circlewidth = 30;
                        int adjustduetowindowwidth = 90;
                        EllipseInfo einfo = new EllipseInfo();
                        Ellipse ellipse = new Ellipse()
                        {
                            //Margin = new Thickness(A.X - (circlewidth / 2), A.Y- 90 - (circlewidth / 2), 0, 0),
                            Margin = new Thickness(A.X - (circlewidth / 2), A.Y - adjustduetowindowwidth - (circlewidth / 2), 0, 0),
                            Stroke = new SolidColorBrush(Color.FromRgb(255, 0, 0)),
                            StrokeThickness = circlewidth,
                            Width = circlewidth,
                            Fill = Brushes.AliceBlue
                        };
                        einfo.circle = ellipse;
                        einfo.X = Convert.ToDouble(A.X.ToString());
                        einfo.Y = Convert.ToDouble((A.Y - adjustduetowindowwidth).ToString());
                        einfo.oriX = Convert.ToDouble(A.X.ToString());
                        einfo.oriY = Convert.ToDouble((A.Y - adjustduetowindowwidth).ToString());
                        einfo.Direction = 0;
                        einfo.NumberOfRotation = 0;
                        einfo.running = 1;

                        ellipse.MouseDown += ellipse_MouseDown;
                        ellipse.MouseDown += ellipse_MouseUp;
                        ellipse.MouseMove += ellipse_MouseMove;

                        if (EllipseList.Count > 0)
                        {
                            einfo.angle = 0;// Math.Atan(Math.Abs(einfo.Y - EllipseList[EllipseList.Count - 1].oriY) / Math.Abs(einfo.X - EllipseList[EllipseList.Count - 1].oriX));
                            einfo.oriangle = Math.Atan(einfo.Y - EllipseList[EllipseList.Count - 1].oriY) / (einfo.X - EllipseList[EllipseList.Count - 1].oriX);
                        }
                        clearLinesColor();
                        ellipse1 = ellipse;
                        ellipse.Tag = ellipse;
                        ellipseid = ellipseid + 1;
                        einfo.Id = ellipseid;
                        Canvas.SetZIndex(ellipse, maxzindex - ellipseid);
                        myCanvas.Children.Add(ellipse);
                        EllipseList.Add(einfo);

Here can not change color

for(int i=0; i<=5; ++i)
                {
                    this.Dispatcher.Invoke((Action)(() =>
                    {
                        EllipseList[i].circle.Stroke = new SolidColorBrush(Color.FromRgb(0, 255, 0));
                        EllipseList[i].circle.Fill = Brushes.AliceBlue;
                        //EllipseList[i].circle.Stroke = blue;
                        myCanvas.UpdateLayout();
                    }));
                    Thread.Sleep(1000);
                    this.Dispatcher.Invoke((Action)(() =>
                    {
                        EllipseList[i].circle.Stroke = new SolidColorBrush(Color.FromRgb(255, 0, 0));
                        EllipseList[i].circle.Fill = Brushes.AliceBlue;
                        //EllipseList[i].circle.Stroke = red;
                        myCanvas.UpdateLayout();
                    }));
                }

MEALY