The Rainbow Gem is an unimplemented item in Sonic the Hedgehog (2006).
This item would have given the characters their Super State. Though never implemented into the game due to rushed development, this item can be found within the game's files. It could be restored if one were to hack the game, but would not be fully functional.
- The gem was originally going to be multicolored, which was a nod to the seven Chaos Emeralds.