No! Rather, the stain has covered their hearts of that which they were earning.
كَلَّا ۖ بَلْ ۜ رَانَ عَلَىٰ قُلُوبِهِمْ مَا كَانُوا يَكْسِبُونَ
The heart develops black spots due to sins
the Messenger of Allah ﷺ said, “When the servant ˹of Allah˺ commits a sin, a black spot appears upon his heart. If he repents, it is polished away. But if he repeats, ˹the black spot˺ increases until it grows large in his heart. That is the "rān" that Allah mentions in His Book: “Nay! But on their hearts is the rān...” [Muṭaffifīn 83:14]
قَالَ رَسُولُ اللَّهِ ﷺ «إِذَا أَذْنَبَ الْعَبْدُ نُكِتَ فِي قَلْبِهِ نُكْتَةٌ سَوْدَاءُ۔ فَإِنْ تَابَ صُقِلَ مِنْهَا فَإِنْ عَادَ زَادَتْ حَتَّى تَعْظُمَ فِي قَلْبِهِ فَذَلِكَ (الرَّانُ) الَّذِي ذَكَرَهُ اللَّهُ ﷻ {كَلَّا بَلْ رَانَ عَلَى قُلُوبِهِمْ} [المطففين 14]»