fly on the wall
you have but-face.
But shouldn't it be black = ashes then? She has walked/is walking through the fire = burned.
Maybe. But if you burn yourself, it turns red, doesn't it? Or, if something's still on fire, it's red...I don't think the "walking through the fire" bit of OMWF was supposed to insinuate that Buffy was burned up. Just, burning. On the brink of burning up/dying. She even starts to literally burn up, before Spike stops her.
Like I said, it's just a theory. 🙂