What is incumbent upon me after performing ghusl on the sixth day upon seeing yellowish discharge, then seeing the white discharge on the eighth day without performing ghusl, and then performing ghusl again on the eleventh day after reading that yellowish discharge is not considered a sign of purity, and how many days do I need to make up?

Yellow discharge connected to blood is considered menstruation. If the questioner performed ghusl (ritual bath) while yellow discharge connected to blood was present, her ghusl was not valid. She should have performed ghusl upon seeing purity, marked by one of its two signs.

If she saw purity on the eighth day but did not perform ghusl until the eleventh day, she must make up the prayers of three days. If she became pure before that, she must make up all the prayers she performed without proper purification. It is safer to make them up, in agreement with the majority of scholars.

As for fasting, she must make up all the days she missed. Her fasting after seeing purity but before performing ghusl is valid, as ghusl from menstruation is not a condition for the validity of fasting. However, if she fasted while menstruating, her fast is not valid. She must make up all the days she was menstruating or the days she missed, thinking her menstruation was still present.