procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
begin
  //売上がマイナスなら赤く表示
  if (Column.FieldName = 'URIAGE') and
    (Column.Field.DataSet.FieldByName('URIAGE').AsCurrency < 0) then
    DBGrid1.Canvas.Font.Color := clRed;

  //偶数行の色を変える
  if  Column.Field.DataSet.RecNo Mod 2  =  0 then
    if (not (gdSelected in State))  then             (←追加）
      DBGrid1.Canvas.Brush.Color := clSkyBlue;

  //描画
  DBGrid1.DefaultDrawColumnCell(Rect,DataCol,Column,State);

end;