Is it necessary to repeat the ghusl if one of the signs of purity appears after having performed ghusl following the other sign? And is it obligatory to perform ghusl immediately upon dryness, or should one wait to be sure, and is there a difference of opinion among scholars regarding this?

Scholars have preponderated that yellowish and brownish discharges are considered menses during the period of a woman's accustomed cycle, but not outside of it. A woman becomes pure upon seeing one of two signs: dryness (al-jufūf) or the white discharge (al-qaṣṣah al-bayḍāʾ). When she sees either of these, ghusl (ritual bath) becomes obligatory upon her, and it is more cautious to hasten with it upon seeing dryness. Some scholars are of the view that a woman may wait for a day and a half after seeing dryness if it is within her accustomed period, because blood flows and then stops. However, if she sees what indicates the cessation of blood, such as dryness at the end of her accustomed period or the white discharge, ghusl becomes immediately obligatory upon her.