Okay, I've just had a facepalm moment. And I mean, a few minutes ago.
I was going through an old Gale of Darkness file, getting ready to erase it so I can go on a Duskull hunt. I was just rummaging for a few odd pokemon that looked like they might be useful as breeders down the road. As I'm looking, I see a yellow Growlithe. And I get all excited because I LOVE shiny Arcanine and I've always wanted to see a shiny pokemon in 3D (cuz I'm a silly nerd like that). Then I look on my "permanent" file of Gale of Darkness to confirm that this is, in fact, the alternate colouration, because I know that there were some colouring mistakes in the game
and...
It's the regular colouration. Normal growlithe all look yellow, the shiny ones just have a little extra yellow added to the muzzle. To whoever did the colours for the pokemon in this game, I suggest they be tested for colourblindness, or else not work when overtired. And also, I'd like to palm their face. Hard.
Fail.