وَعَنْ أُمِّ عَطِيَّةَ رَضِيَ اَللَّهُ عَنْهَا
قَالَتْ: «كُنَّا لَا نَعُدُّ اَلْكُدْرَةَ وَالصُّفْرَةَ بَعْدَ اَلطُّهْرِ شَيْئًا»
After we were pure, we did not consider the yellow or muddy discharge to be anything (i.e. of the menses blood).
Bulugh al-Maram 171, Book 1, The Book of Purification, Hadith 171. 1 min read