Hawzah News Agency – Two questions answered by Ayatollah Khamenei pertaining to the rules of najis substances
Q: If a faint bloodstain remains on the dress after it has been washed, is that faint-colored stain najis?
A: If it is not the blood itself and only the color remains, it is pure.
Q: What is the rule pertaining to a spot of blood present in an egg?
A: It is considered pure, but eating it is ḥarām.
Source: https://www.leader.ir/en/book/32/Practical-Laws-of-Islam