Do the intermittent dry periods during the discharge of brown or yellow secretions after the cessation of menstrual bleeding count as purity, or must one wait for the white discharge?

Purity from menstruation or post-natal bleeding (nifas) is achieved by one of two signs: dryness (al-jufūf) or the white discharge (al-qaṣṣah al-bayḍāʾ). If a woman ascertains dryness after her usual period has ended, she is pure, and any subsequent brownish or yellowish discharge is not considered menstruation. However, if she does not ascertain dryness, then the aforementioned discharges are considered remnants of menstruation until dryness or the white discharge occurs, as they are types of menstrual bleeding if they appear during the usual menstrual period. For a woman whose custom is to achieve purity only by the white discharge or by both signs, it is recommended for her to wait for it until the end of the preferred time for prayer.