After becoming pure (from menstruation), we would not consider brownish and yellowish discharges to be of any significance

The female Companion ’Umm ‘Atiyyah (may Allah be pleased with her) reported that after attaining purity from menstruation, women, during the lifetime of the Prophet (may Allah's peace and blessings be upon him), would not consider the fluid discharged from the vagina - which tends to be blackish or yellowish - to be menses. Hence, such a discharge did not stop them from praying or fasting.