procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
DataCol: Integer; Column: TColumn; State: TGridDrawState);
begin
if gdSelected in State then
begin
TDBGrid(Sender).Canvas.Brush.Color := clOlive;
TDBGrid(Sender).DefaultDrawColumnCell(Rect, DataCol, Column, State);
end;
end;