Is it obligatory to perform ghusl after the discharge of brownish spots that continue for two or three days instead of the usual menstrual blood, and is it obligatory to break the fast in Ramadan when these spots are discharged?

Brown spots from al-kudrah are considered menses if they appear during the usual period, provided they last for a full day and night. If their duration is less than that, they are not considered menses according to the majority of scholars.