Wow- that's a huge difference! The good thing about this snake is you're NEVER going to have a feeding problem. I would establish the baby as a container-feeder- you do NOT want to feed a Florida king in the viv. If he's a FK, expect a big adult snake. My Janine is about 1400 grams and still growing- twice the weight of a big cornsnake. She is very gentle, however, when not being fed. Never a tail rattle, defensive strike, nothing like that. An Appalachicola king will be somewhat smaller, but still much more stout than an adult corn. The temperament is similar. If you have any picky feeders, he will be happy to eat the leftovers! And my FK is always eager to eat infertile snake eggs, too.
I _would_ expect the orange to fade to a golden yellow, and actually the whole snake should become more gold.