procedure TForm1.StringGrid1DrawCell(Sender: TObject; ACol, ARow: Integer;
Rect: TRect; State: TGridDrawState);
begin
with StringGrid1 do
with Canvas do
begin
if (ARow>=FixedRows)and(ACol>=FixedCols) then Brush.Color:=clWhite;
FillRect(Rect);
end;
end;