6dc5455c____The_Coppermind___17th_Shard__Entry
[Chapter] 19 [Entry] 
Yes, the ash was black. No, it should not have been. Most common ash has a dark component, but is just as much gray or white as it is black. Ash from the ashmounts . . . it was different. Like the mists themselves, the ash covering our land was not truly a natural thing. Perhaps it was the influence of Ruin's power—as black as Preservation was white. Or, perhaps it was simply the nature of the ashmounts, which were designed and created specifically to blast ash and smoke into the sky.
The Hero of Ages/Epigraphs - The Coppermind - 17th Shard
Entry