Time Delay not working properly

[JustJohn]

Ok, I have a chess board application. The application has 64 panels within a groupbox. These panels are identified with the expression CHessBoardPanel s{x,y). I am using this to change the background color of the panels. I want a small delay in between where the chessPanel.Back Ground changes to red and when the panels turn back to white.(approxim ately 1 to 2 second delay)
I have tried the Sleep function but it basically locks the application up till the task have been complete

Here is the code which I have tried:

    for (int Row = 7; Row > 3; --Row)
                {
                    chessBoardPanels[ Column ,Row].BackColor = Color.Red;
                    ++Column;
                    //Add text to Moves TextBox
                    MovesText.AppendFormat("WhtB               {0}                   {1}{2}"
                    , ColumnText,RowText,Environment.NewLine);
                    MovesTxt.Text = MovesText.ToString();
                    ++ColumnText;
                    --RowText;
                                       
                }
                //Start White Horizonal Drill 
                Column = 0;
                Thread.Sleep(5000);
                for (int Row = 7; Row > 4; --Row)
                {
                    chessBoardPanels[Column, Row].BackColor = Color.White;
                    ++Column;
                    //Add text to Moves TextBox
                    MovesText.AppendFormat("WhtB               {0}                   {1}{2}"
                    , ColumnText, RowText, Environment.NewLine);
                    MovesTxt.Text = MovesText.ToString();
                    ++ColumnText;
                    --RowText;
                  
                }