이런방법도 있습니다. 간단히 ^^
procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject;
  const Rect: TRect; DataCol: Integer; Column: TColumn;
  State: TGridDrawState);
var
   RH,R : Integer;
begin
   RH := Rect.Bottom - Rect.Top;
   R  := (Rect.top div RH) - 1;
   R  := R mod 2;
   if (R = 0) then begin
       (Sender as TDbGrid).canvas.brush.Color := clInfoBk;
       (Sender as TDbGrid).canvas.font.Color  := clWindowText;
       (Sender as TDbGrid).canvas.FillRect(Rect);
       (sender as TDbGrid).DefaultDrawColumnCell(Rect, DataCol, Column, State);
   end
   else begin
       (sender as TDbGrid).DefaultDrawColumnCell(Rect, DataCol, Column, State);
   end ;
end;

hsr////////////////////////////////////////////////////////////////
좀 어색하지만.....
아래처럼해보세요.

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DB, DBTables, Grids, DBGrids;

type
  TForm1 = class(TForm)
    DBGrid2: TDBGrid;
    DataSource2: TDataSource;
    Table2: TTable;
    procedure DBGrid2DrawColumnCell(Sender: TObject; const Rect: TRect;
      DataCol: Integer; Column: TColumn; State: TGridDrawState);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
    SaveWndProc: TWndMethod;
    procedure WndProc(var Message: TMessage);
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.DBGrid2DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
var
  row : integer;
begin
   with TDBGrid(Sender) do begin
         row := MouseCoord(Rect.Left, Rect.Top).Y;
         if ( row mod 2)=0 then begin
            Canvas.Brush.Color :=clBlack;
            Canvas.Font.Color:=clWhite;
         end
         else begin
            Canvas.Brush.Color :=clWhite;
            Canvas.Font.Color:=clBlack;
         end;
         DefaultDrawColumnCell(Rect, DataCol, Column,[]);
    end;
end;

procedure TForm1.WndProc(var Message: TMessage);
begin
  if (Message.Msg = WM_HSCROLL) or (Message.Msg = WM_VSCROLL) then
  begin
      DBGrid2.Repaint;
  end;

  SaveWndProc(Message);
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
    SaveWndProc := DBGrid2.WindowProc;
    DBGrid2.WindowProc := WndProc;
end;

end.