procedure TMainForm.GrayWControl(WCtrl: TWinControl);
procedure GrayCtrl;
const
Color1 = clWhite;
Color2 = clBlack;{}
{Color1 = $00AAAAAA;
Color2 = $00555555;{}
var
DesktopDC, MemDC: HDC;
NewBitmap, OldBitmap: HBITMAP;
I, J: Integer;
begin
DesktopDC := GetDC(WCtrl.Handle);
try
  MemDC := CreateCompatibleDC(DesktopDC);
  if MemDC <>0 then
  begin
    NewBitmap := CreateCompatibleBitmap(DesktopDC, 32, 32);
    if NewBitmap <>0 then
    begin
      OldBitmap := SelectObject(MemDC, NewBitmap);
      for I := 0 to 31 do
        for J := 0 to 31 do
          if (I + J) and 1 = 0 then
            SetPixel(MemDC, I, J, Color1)
          else
            SetPixel(MemDC, I, J, Color2);
      { Paint }
      J := 0;
      while J <Screen.Height do
      begin
        I := 0;
        while I <Screen.Width do
        begin
          BitBlt(DesktopDC, I, J, 32, 32, MemDC, 0, 0, SRCAND);
          Inc(I, 32);
        end;
        Inc(J, 32);
      end;
      { Delete objects }
      DeleteObject(NewBitmap);
      SelectObject(MemDC, OldBitmap);
    end;
    DeleteDC(MemDC);
  end;
finally
  ReleaseDC(Handle, DesktopDC);
end;
end;
var N: Integer;
begin
for N:=0 to WCtrl.ControlCount-1 do
 if WCtrl.Controls[N] is TWinControl then begin
  GrayWControl(TWinControl(WCtrl.Controls[N]));
  GrayCtrl;
 end;
GrayCtrl;
end;

procedure TAboutForm.WMEXITSIZEMOVE(var Message: TMessage);
begin
 inherited;
 MainForm.GrayWControl(MainForm);
end;

: The window enters the moving or sizing modal loop when the user clicks the window's title bar or sizing border, or when the window passes