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.”

حَدَّثَنَا الْعَبَّاسُ بْنُ مُحَمَّدٍ الدُّورِيُّ، حَدَّثَنَا يَحْيَى بْنُ أَبِي بُكَيْرٍ، حَدَّثَنَا شَرِيكٌ، عَنْ عَاصِمٍ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ ـ ﷺ ـ قَالَ " أُوقِدَتِ النَّارُ أَلْفَ سَنَةٍ فَابْيَضَّتْ ثُمَّ أُوقِدَتْ أَلْفَ سَنَةٍ فَاحْمَرَّتْ ثُمَّ أُوقِدَتْ أَلْفَ سَنَةٍ فَاسْوَدَّتْ فَهِيَ سَوْدَاءُ كَاللَّيْلِ الْمُظْلِمِ " .