[roman]

Hola Caro,

Puedes hacerlo cambiando DBGrid.Canvas.Brush.Color:

Código Delphi [-]
procedure TForm1.DBGrid1DrawColumnCell(
  Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
begin
  if tu_condición and (gdSelected in State) then
    DBGrid1.Canvas.Brush.Color := clRed;

  DBGrid1.DefaultDrawColumnCell(Rect, DataCol, Column, State);
end;

// Saludos