Is light pink blood that appears at the beginning and end of the menstrual cycle, and is sometimes intermittent, considered menstruation that prohibits prayer and fasting, given that dark blood appears in the middle of the cycle?

Slight bleeding in the first two days is not considered menses unless it continues for a day and a night. A ghusl (definition) (ritual bath) is not required for its cessation. As for the blood that returns at the end of the menstrual period, it is considered menses if it appears during a time suitable for menstruation. A ghusl is required upon seeing purity, and then the woman returns to the state of menses if the bleeding recurs.