Does the dryness, followed by a small amount of moisture, after the cessation of menstrual bleeding, count as purity (tahara) that necessitates ghusl (ritual bath) and prayer, or must ghusl and prayer be repeated and the prayers performed during the discharge of the yellowish fluid be made up?

A woman recognizes purity by one of two signs: dryness (which is the complete cessation of blood, yellowness, and turbidity) or the white discharge (a fluid women recognize as the cessation of menstruation). Yellowness and turbidity connected to menstruation are considered menstruation. Therefore, the yellowness you saw connected to menstruation is considered menstruation, and performing ghusl (definition) (ritual bath) while it is present is not sufficient. Purity occurred with the dryness, so you must repeat ghusl after seeing it, and repeat the prayers you performed after seeing purity and before performing ghusl, because they were not validly performed. As for the prayers you performed while the yellowness was present, they are not valid and are not obligatory upon you, because you were menstruating, and you are not required to make them up.