(a) Urwah bin al-Zubayr (may Allah have mercy on him) says: Fatimah bint Abi Hubaysh (may Allah be pleased with her) told me that she instructed Asma' (may Allah be pleased with her), or Asma' (may Allah be pleased with her) herself told me that Fatimah bint Abi Hubaysh (may Allah be pleased with her) instructed her, to ask the Messenger of Allah (peace and blessings be upon him) about it. He (peace and blessings be upon him) instructed her: "She should sit out the days she used to sit out (that is, her days of menstruation), then take a ritual bath."
(b) It is reported from al-Zuhri (may Allah have mercy on him), from Urwah (may Allah have mercy on him), from Asma' (may Allah be pleased with her), concerning Fatimah bint Abi Hubaysh (may Allah be pleased with her); he mentioned a story about how she should take her ritual bath, in which it says: when she sees yellowness on top of the water.
(c) It is reported from Urwah (may Allah have mercy on him) concerning Sayyidah Fatimah (may Allah be pleased with her); he mentioned her prolonged bleeding, and that the Prophet (peace and blessings be upon him) instructed her to refrain from the prayer when she saw black blood.
(d) The narration of Hisham bin Urwah (may Allah have mercy on him), from his father (may Allah have mercy on him), from Aishah (may Allah be pleased with her), indicates that Fatimah bint Abi Hubaysh (may Allah be pleased with her) used to distinguish between the two kinds of blood. The narration of Suhayl is questionable, and so is the chain of his hadith; moreover, the second narration from him indicates that he did not preserve it as he should have.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحيض / 1573