procedure TForm1.DBGrid3DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
begin
  if gdselected in state then
  begin
    dbgrid3.Canvas.Brush.color:=clred;
    dbgrid3.defaultdrawcolumncell(rect,datacol,column,state);
  end;
end;