Is the fast of a woman who purified before Fajr and fasted, then saw yellowish discharge around Dhuhr, valid?

If a woman sees purity before Fajr and fasts, her fast is valid, and the yellowish discharge after purity has no effect, due to the saying of Umm Atiyyah (may Allah be pleased with her): "We used not to consider the

brownish or yellowish discharge after purity as anything significant."