Does the redness which stays after washing clothes from blood stain, invalidate prayer?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

The blood stain that remains after washing clothes does not have any affect if it is difficult to remove the colour. An-Nawawi said:  'The colour or smell which is difficult to remove does not any effect.'

Moreover, Al-Mardaawi said: 'The colour or smell or both of them do not have any effect, according to the correct opinion of the Shaafi’ee school.'

Allaah Knows best.