If an impure item comes in contact with a pure item, impurity will only transfer, if it is visible.”
Is it possible to provide evidence of this from the Qur’an and/or Sunnah? I am still having great difficulty adhering to instructions given to me to overcome the problem.
Answer:
In the name of Allah, the most Beneficent, the most Merciful.
Imam Shurunbulali 
, a famous Hanafi scholar has written,
“A cloth does not become impure if it has been struck by a wind that has blown over some filth, unless the filth becomes visible on the clothes.” (Nurul Idah p.87)
There is a hadith which says that as long as the traces of the filth is visible on the clothes it is necessary to remove it. It is narrated by Saaidah Aaisha 
that she was asked regarding a woman in her menses whose clothes had some traces of blood. She ordered her to wash it and if the traces cannot be removed then to wash it off with a “sufrah” (soap etc…) (Sunan Abu Dawud p.58 v.1)
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham