What is the ruling on yellow discharge (ṣufrah) and brownish discharge (kudrah) before and after menstruation?

Yellowish and brownish discharges during the period of purity (Tuhr) are considered purity, whether before menstruation or after purification from it. This is based on the narration of Umm Atiyyah (may Allah be pleased with her) who said: "We used not to consider yellowish and brownish discharges as anything (i.e., as menstruation) while we were in the period of purity." The implication of this Hadith is that if they occur during the period of menstruation, they are considered menstruation.