procedure ShadeIt(f: TForm; c: TControl; Width: Integer; Color: TColor); 
var 
  rect: TRect; 
  old: TColor; 
begin 
  if (c.Visible) then 
  begin 
    rect := c.BoundsRect; 
    rect.Left := rect.Left + Width; 
    rect.Top := rect.Top + Width; 
    rect.Right := rect.Right + Width; 
    rect.Bottom := rect.Bottom + Width; 
    old := f.Canvas.Brush.Color; 
    f.Canvas.Brush.Color := Color; 
    f.Canvas.fillrect(rect); 
    f.Canvas.Brush.Color := old; 
  end; 
end; 

procedure TForm1.FormPaint(Sender: TObject); 
var 
  i: Integer; 
begin 
  for i := 0 to Self.ControlCount - 1 do 
    ShadeIt(Self, Self.Controls[i], 3, clBlack); 
end;