Fireworks won't show up in creative inventory

There's just too many combinations to list all the fireworks.
So Working as Intended

Incomplete, AND intended.

You have to craft a working firework yourself, whether it be in creative or not.
Also, using just the firework star in the creative inventory won't work, you must make a colored one.

Mustek is correct. The number of total rockets you can craft has 136 digits. I calculated it and will be making a post about it on the forums.

The rocket was in originally, but Dinnerbone removed it for the reason stated above.

I'd personally say the useless star should be removed, and replaced with the firework. The default firework which was previously there could be used as a noisemaker, if nothing else. The star, conversely, does absolutely nothing.

The star will be removed in a future version, Dinnerbone forgot to take it out.

if you use wool or read www.gamepieda.minecraftwiki.com
you may learn something mustek

There are only 16 unique types of wool.

There are around 14,577,845,030,668,508,850 unique firework stars.

There are nearly 139,911,465,022,395,945,977,874,744,330,410,468,287,659,018,659,515,696,851,595,394,340,429,067,951,320,979,023,437,757,490,531,565,292,479,346,683,118,313,168,299,785,759,119,053 unique firework rockets, and that's just counting the ones you can craft in survival!

The comparison doesn't really work.