Quran 3:106 from Surah Aal-i-Imraan on Divine Marvels.
يَوۡمَ تَبۡيَضُّ وُجُوهٞ وَتَسۡوَدُّ وُجُوهٞۚ فَأَمَّا ٱلَّذِينَ ٱسۡوَدَّتۡ وُجُوهُهُمۡ أَكَفَرۡتُم بَعۡدَ إِيمَٰنِكُمۡ فَذُوقُواْ ٱلۡعَذَابَ بِمَا كُنتُمۡ تَكۡفُرُونَ
English translation: (On the) Day would become white (some) faces and would become black (some) faces As for those whose turn black [their] faces Did you disbelieve after your belief Then taste the punishment for what you used to disbelieve
Transliteration: yawma tabyaddu wujuhun wataswaddu wujuhun fa-amma alladhina is'waddat wujuhuhum akafartum ba'da imanikum fadhuqu al-'adhaba bima kuntum takfuruna