Zebrando um DBGrid

Tenta usar isso:

procedure TForm1.DBGrid1DrawDataCell(Sender: TObject; const Rect: TRect;
Field: TField; State: TGridDrawState);
begin
if gdFocused in State then
with (Sender as TDBGrid).Canvas do
begin
Brush.Color:=clRed;
FillRect(Rect);
TextOut(Rect.Left, Rect.Top, Field.AsString);
end;
end;

procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
DataCol: Integer; Column: TColumn; State: TGridDrawState);
begin
If odd(DBGrid1.DataSource.DataSet.RecNo) then
begin
DBGrid1.Canvas.Font.Color:= clblack;
DBGrid1.Canvas.Brush.Color:= clsilver;
end
else
begin
DBGrid1.Canvas.Font.Color:= clBlack;
DBGrid1.Canvas.Brush.Color:= clWhite;
end;
DBGrid1.Canvas.FillRect(Rect);
DBGrid1.Canvas.TextOut(Rect.Left+2,Rect.Top,Column.Field.AsString);
end;