Is it permissible to pray during the three days when menstrual bleeding stops between two periods of blood, and is performing ghusl upon seeing a yellow discharge valid?

It is obligatory for you to pray during the three days when you experience purity between periods of bleeding. When you see blood, you are in a state of menstruation. When it ceases, and you observe dryness or a white discharge, you become pure, and fasting and prayer become obligatory for you. If the bleeding returns, you are again in a state of menstruation, provided that the total duration does not exceed fifteen days. If it exceeds that, then you are in a state of irregular bleeding (Istihada), and you must perform ablution for each prayer after its time has begun. Your ghusl (ritual bath) before each prayer due to the yellowish discharge you see is an excessive measure. This yellowish discharge, if preceded by menstrual blood, is considered menstruation. However, if it is preceded by a period of purity, its ruling is that of normal discharges, based on the statement of Umm Atiyyah (may Allah be pleased with her): "We used not to consider the yellowish or brownish discharge after purity as anything."