[NumLock]

Do not write an OnDrawDataCell event handler. OnDrawDataCell is obsolete and included for backward compatibility. Instead, write an OnDrawColumnCell event handler.

используй OnDrawColumnCell. вкратце:

Код:

procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
    DataCol: Integer; Column: TColumn; State: TGridDrawState);
begin
  if (OraQuery1.FieldByName('KODNAIM').AsInteger mod 2)=0 then
    DBGrid1.Canvas.Brush.Color:=clRed;
  DBGrid1.DefaultDrawColumnCell(Rect, DataCol, Column, State);
end;