Is it permissible to pray and fast tomorrow, given the continued emission of blood after ten days from the start of the bleeding that was considered menstruation, and which was preceded by the emission of brown or pink discharge or light red blood thirteen days before the usual time of menstruation?

Brown discharge is not considered menses as long as it is outside the usual period and not preceded by blood. Red blood is considered menses if it is seen at a time when it can be menses, meaning it is preceded by a period of purity not less than thirteen days. If red blood appears after less than thirteen days of purity, it is istihada (non-menstrual vaginal bleeding). However, if it appears after thirteen days or more, it is menses, and the woman remains in her menstrual state as long as the blood continues. If the blood stops for less than fifteen days, the entire period is considered menses. But if the duration of the blood exceeds fifteen days, it is istihada. So, if red blood continues for ten days and it is at a time suitable for menses, the woman remains in her menstrual state and does not pray or fast until the blood stops. If the duration exceeds fifteen days, she is mustahada (experiencing istihada).