What is the ruling on the intermittent blood that comes five days after menstruation, first red, then lighter, then pink with a fluid, and what is the duration of the menstrual period in this case, and what about the ruling on previous prayers and fasting, knowing that ghusl was performed after dryness?

If your usual period has ended and you have seen dryness or the white discharge, then you have become pure and it is obligatory for you to perform ghusl (definition), pray, and fast. The small amount of blood that appeared for fifteen minutes on the sixth and seventh days is irregular bleeding (istihadah (definition)) and does not invalidate the soundness of prayer and fasting. However, if your usual period has not ended, scholars differ: some consider the blood and disregard the intervening purity, in which case you must purify yourself, fast, and pray whenever you see purity; others consider all of it menstruation. The pinkish blood on the eighth day is a brownish discharge (kudrah), and kudrah during a period of purity is not considered anything, based on the Hadith (definition) of Umm Atiyyah: "We did not consider the yellowish and brownish discharges to be anything." Your prayers and fasting are valid, and your usual period remains five days.