When is a woman clean who experiences frank bleeding for five or six days, then the color becomes brown for three days, then yellow which gradually fades, then a reddish-brown color appears slightly for two days on the fourteenth day? And is it permissible for her to fast the days when the bleeding stops, or is it necessary for her to make them up?

The days of blood, yellowness, and turbidity exceed fifteen days, and the period of purity is less than thirteen days. Based on this, you are experiencing Istihada (prolonged non-menstrual bleeding).

If you have a previous customary period, observe it as your menses, and whatever exceeds it is Istihada. If you do not have a customary period, then act according to discrimination (tamyezz): observe the period of known red blood as menses, and anything else is Istihada, for which you perform ghusl (definition) (ritual bath) and pray.