Must I make up the Dhuhr and Asr prayers if menstruation stops after the time for Asr and before Maghrib?

A woman must initiate ghusl immediately upon seeing purity, as stated by Ibn Abbas (may Allah be pleased with them both). Your delay in performing ghusl until you missed the prayer is an error, and you must make up the Dhuhr and Asr prayers, because Asr is a time for Dhuhr when necessary. Yellowish and brownish discharges are considered menstruation if they are connected to blood or occur during the usual period.