If someone performs Ghusl after menstruation and later notices a small brownish, yellowish, or pink spot, is there a need to perform Ghusl again according to Sayid Khamenei's ruling?
If your menstruation days are regular and you performed the Ghusl after the end of your menstruation days, then blood after your menstruation days is not menstruation but just Istehadha in which you need to perform Salah after performing Wudhu for every Salah.
If posts are not blood, then no Ghusl is obligatory again.
Wassalam.