ENOfficial
It was narrated from Abu Hurairah that the Prophet (ﷺ) said: “The Hell-Fire was kindled for one thousand years and turned white. Then it was kindled for another thousand years and it turned red. Then it was kindled for another thousand years and it turned black. So it is black like the darkest night.”
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا الْعَبَّاسُ بْنُ مُحَمَّدٍ الدُّورِيُّ، حَدَّثَنَا يَحْيَى بْنُ أَبِي بُكَيْرٍ، حَدَّثَنَا شَرِيكٌ، عَنْ عَاصِمٍ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ ـ صلى الله عليه وسلم ـ قَالَ " أُوقِدَتِ النَّارُ أَلْفَ سَنَةٍ فَابْيَضَّتْ ثُمَّ أُوقِدَتْ أَلْفَ سَنَةٍ فَاحْمَرَّتْ ثُمَّ أُوقِدَتْ أَلْفَ سَنَةٍ فَاسْوَدَّتْ فَهِيَ سَوْدَاءُ كَاللَّيْلِ الْمُظْلِمِ " .
sunnah.com