Is ghusl required after the white and yellow discharges that continue for several days after menstruation, and are the spots of blood that follow for two or three days menstrual blood or ovulation blood, and are prayer and fasting obligatory in both cases?

If a woman sees black menstrual blood, she must refrain from prayer and fasting. When she sees purity, she performs ghusl (ritual bath), prays, and fasts.

If she sees yellow or brownish discharges (al-ṣufrah wal-kudrah) during her regular menstrual cycle, they are considered menstruation, so she stops praying until they cease and she performs ghusl.

As for white discharges, they are not menstruation.

If she sees yellow or brownish discharges outside her habitual cycle, they are not menstruation, but they do invalidate ablution (wudu'). She should perform wudu' for each prayer if they are continuous.

Any blood a woman sees before the expiry of fifteen days from the start of menstruation is considered menstruation.

However, blood seen after fifteen days from the start of menstruation is ruled as istihadah (non-menstrual vaginal bleeding), so she purifies herself from it, performs wudu', and prays.