Is purification and the rulings of istihadah obligatory for one whose menstruation ceased for two and a half months, then returned a week before Ramadan in the form of light discharge, then red blood flowed for 8 days?

If the discharge is yellow or brownish, it is not menstruation. Menstruation is the days when blood flows.

However, if the discharge is blood, then the entire duration is considered menstruation, as long as it does not exceed fifteen days.

If the duration exceeds fifteen days, the woman is considered to be in a state of istihadah (non-menstrual bleeding).