I have a theory

[Sonic The Hedgehog]

I also posted this theory on the SA2 discussions. In Sonic The Fighters, there's 8 Chaos Emeralds. Sonic The Fighters is exclusively in the classic timeline and not the modern on. So here's my theory. What if Classic Sonic found Tails' fake Chaos Emerald in SA2 and brought it back with him to the classic timeline, allowing there to be 8 emeralds in STF (Sonic the Fighters)? Also, that 8th emerald is Orange. a very similar color to yellow. Maybe the Classic timeline made it's color change. Just saying.

[Douknodefox]

It's just a theory... A GAME THEORY!!! Still think it's a really cool theory.

[ForteDS]

I wouldn't try fixing Sonic the Fighters chaos emeralds. There are 8 emeralds, none are White/Silver. There's always a silver emerald, except Fighters.

The fake emerald in SA2 was every bit as yellow/gold as the real one. I'm not sure how they would know which is which without already knowing which is which, but they look exactly the same.

If you are looking for a place to pull an orange Chaos Emerald, look to the GameGear games instead. There are six emeralds there, one is orange in Triple Trouble and Chaos.

[Sonic The Hedgehog]

Idk if the game gear games are a good source. The canonicity with them is confusing. Plus in most of the games, there's only 6 emeralds.

[Sonic The Hedgehog]

Also, I'm pretty sure Sonic the Fighters has to be canon to the classic timeline because it introduces Bean and Bark, and the illusions of Team Hooligan are in Mania, which is absolutely canon.