Is the Hadith of Hafsa (may Allah be pleased with her), "We used to consider the yellowish and brownish discharge as istihadah (non-menstrual bleeding)," weak, and what is its meaning if it is authentic?

Perhaps the questioner is referring to the authenticated narration from Hafsa bint Sirin, from Umm Atiyyah, with the wording: "We did not consider the yellowish or brownish discharge after ritual purity (tuhr) to be anything." This is a sound hadith narrated by Abu Dawud and others, and by Al-Bukhari with the wording: "From Umm Atiyyah, who said: 'We did not consider the brownish or yellowish discharge to be anything.'" Its meaning is that the yellowish and brownish discharge after the end of menstruation is not considered menstruation. And the hadith of Aisha, which indicates that brownish and yellowish discharge is menstruation, is understood to refer to their occurrence during the time of menstruation and before ritual purity (tuhr).