Endri, on 28 January 2012 - 02:56 PM, said:
Incidentally, the second Special Stage's Chaos Emerald in Sonic & Knuckles is also orange. The second Super Emerald is also orange in Sonic 3 & Knuckles.
Further, neither game can quite make up its mind about the colour of that second emerald elsewhere. It's always orange on the save screen and when Knuckles knocks it out of you in Angel Island, and it's always yellow on the chaos emeralds results screen, for both variants. The only change in S&K is to the colour of the emerald within the stage itself as you pointed out.
Amusingly, if they hadn't changed it to orange within the stage, S&K alone would have been totally consistent on the use of yellow, since the emeralds aren't seen in any other context. As it is, it's as inconsistent as every other S3 variant.
The reason the special stage selection doesn't work in S&K alone is because you need debug mode to do it, for some reason. If you can poke at RAM to give yourself that power, it'll work just like the other two.