(It's blue, it's just appears gray because its flashing)
and you should end up like this after all are collected:
| All Blue Chaos Emeralds |
|
This is a trick I picked up when I first got Sonic way back when I was about 12. What you do is, in debug mode, press B to become items in the Special stages. Head directly left to the outside. drop and press left. You should end up here:
(It's blue, it's just appears gray because its flashing) and you should end up like this after all are collected:
|