Is blood that appears after ghusl and prayer considered istihadah (irregular bleeding) or is it still menstruation, given that the habit may extend to the eighth day?

If blood appears after seeing the signs of purity (ṭuhr), it is considered menstruation (ḥayḍ) and necessitates ghusl (ritual bath) after its cessation, provided its duration does not exceed fifteen days and nights. As for yellowish (ṣufrah) or brownish (kadira) discharge that appears outside the customary period and is not connected to blood, it is not considered menstruation.