An air burst is best likened to a stage flash in a soft package and suspended in mid-air, providing flash, pop, smoke and optional shower of sparks. The housing should be consumed in the burst, leaving just the small igniter wire.
A loud "pop", considerably quieter than a maroon.
A white flash and puff of smoke. The smoke can be coloured by lighting. Whitish glitter sparks are optional, and add impact to the effect.
These vary according to the type of air burst and what it is close to.
Further details on the Air Burst Clearances page.