Is ritual bathing valid after the cessation of blood and the discharge of very light brown secretions on the eighth day of the menstrual cycle, or must other signs of purity be awaited?

A woman recognizes purity by one of two signs: dryness or the white discharge. She does not perform ghusl before seeing one of them. The yellowish and brownish discharges connected to blood are considered menstruation. Your ghusl while there was brownish discharge connected to blood is not sufficient, and you must perform ghusl after the bleeding stops and you see the sign of purity.