Minecraft wiki entry for Other_data_format, associated text: : Parent tag.
 FireworkTrail: True if this explosion has the Trail effect (diamond).
 FireworkFlicker: True if this explosion has the Twinkle effect (glowstone dust).
 FireworkType: The shape of this firework's explosion. 0 = Small Ball, 1 = Large Ball, 2 = Star-shaped, 3 = Creeper-shaped, 4 = Burst.[needs testing]
 FireworkColor: Array of byte values corresponding to the primary colors of this firework's explosion.
 FireworkFade: Array of byte values corresponding to the fading colors of this firework's explosion.