I concur on the flare-type colors of a battery fire. Unfortunately I've seen a couple up close, but you can see a bunch of them if you look up compilations of either hoverboard battery fires or phone/ tablet battery fires. Funny how those were suddenly everywhere then suddenly disappeared, huh? Anyway, there's a very bright and unnaturally-colored sustained flare pattern with a sharp hissing sound as the energy shoots out of the casing, very bright and hot because it's the same kinds of metal-to-air reactions as actual safety flares. Yellow orange flames can come later as the things around a battery fire catch fire.