OK, saw a video, can't remember where. But, it was a fire on a mega-tree that had random embers floating up from the top of the flame. Some white, some orange and some red. They were wavy as they went up to the top and faded as it went up. Much like a real fire with embers popping up and disappearing.
I've played around with my mega-tree and uses a layer below and added different effects but have yet to duplicate it.
Anyone??