بسم الله الرحمن الرحيم
(Fatwa: 733/723/N=07/1437)
If after having intercourse with wife the visible impurity of the body was washed off and thereafter clothes were worn then due to the hukmi impurity of the body the clothes worn shall not turn impure, as the clothes get impure after real impurity smears with them, not by hukmi impurity. Hence you may offer salah in the same clothes after ghusl, it is alright. There is no need to change the clean and pure clothes like banyan etc.
عن معاوية بن أبي سفيان أنه سأل أخته أم حبيبة زوج النبي صلى الله عليه وسلم هل كان النبي صلى الله عليه وسلم يصلي فى الثوب الذي يضاجعك فيه؟ فقالت : نعم إذا لم يصبه أذى (شرح معانى الآثار 1:41، مطبوعه: مكتبه اشرفيه ديوبند).
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband