Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
bayhaqi:1599Abū ʿAbdullāh al-Ḥāfiẓ > Abū al-ʿAbbās Muḥammad b. Yaʿqūb > al-Ḥasan b. Mukram > Abū al-Naḍr > Muḥammad / Ibn Rāshid > Sulaymān / Ibn Mūsá > ʿAṭāʾ > ʿĀʾishah > Idhā Raʾat al-Marʾah al-Dam Faltumsik

[Machine] Regarding prayer, continue performing it until you see it become white like a washed cloth. Then, when you see that, you should perform ablution and pray. If you see it turn yellow or cloudy after that, then perform ablution and pray. However, if you see it turn red like blood, then perform full ablution and pray.  

البيهقي:١٥٩٩أَخْبَرَنَا أَبُو عَبْدِ اللهِ الْحَافِظُ ثنا أَبُو الْعَبَّاسِ مُحَمَّدُ بْنُ يَعْقُوبَ ثنا الْحَسَنُ بْنُ مُكْرَمٍ ثنا أَبُو النَّضْرِ ثنا مُحَمَّدٌ يَعْنِي ابْنَ رَاشِدٍ عَنْ سُلَيْمَانَ يَعْنِي ابْنَ مُوسَى عَنْ عَطَاءٍ عَنْ عَائِشَةَ أَنَّهَا قَالَتْ إِذَا رَأَتِ الْمَرْأَةُ الدَّمَ فَلْتُمْسِكْ

عَنِ الصَّلَاةِ حَتَّى تَرَاهُ أَبْيَضَ كَالْقِصَّةِ فَإِذَا رَأَتْ ذَلِكَ فَلْتَغْتَسِلْ وَلْتُصَلِّ فَإِذَا رَأَتْ بَعْدَ ذَلِكَ صُفْرَةً أَوْ كَدِرَّةً فَلْتَتَوَضَّأْ وَلْتُصَلِّ فَإِذَا رَأَتْ دَمًا أَحْمَرَ فَلْتَغْتَسِلْ وَلْتُصَلِّ