Sorry I made this a long time ago before I was smart enough to know that
SaintJude1: In reality, the effect of rarified air from a shockwave is invisible and it will thus appear blue, while the edge of the wave appears slightly white from the compacted air
SaintJude1: the atmosphere does not get completely blown away, it is instead rarified within the shockwave, while the shockwave itself is much denser than the surrounding air. shockwaves don't make vacuums. also, relative to the observer, there is still atmosphere behind the shockwave, so it will still appear blue
The blue and black was the atmosphere and air being pushed away by the shockwave
Not how a fireball looks. A fireball would be an about 1 KM (depends on blast yield, this is for an average modern fission bomb) ball of superheated elements known as plasma, the 4th state of matter (5th is bose-einstein condensate, 6th is superfluids and 7th is supersolids.) So instead of being a weird blue/black semicircle it would be an impossibly white glowing ball that would look more like looking into the sun through a giant telescope.
The first moment of a nuke, a fireball appears.
it might be a misconseption of the first moment of a nuclear explosion
right rascii. more like a black hole bomb. but i'll still give it a +1