Is it permissible to pray if you have brown discharge after your periods?
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
No. Brown discharge is also counted as haidh.
You should wait until you see clear white discharge or when the brown discharge stops completely, then you can start praying.
It is not permissible to pray before that.
Only Allah knows best
Written by Alimah Sumeyye Sofu
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 Quduri p.52 Maktabatul Bushra
 al-Hidaya 1/111 Maktabatul Bushra