Gen 2 Old Sprite Colors

Shiny Charizard, personally. I loved how it was purple and teal, but black and red is ok too.
Sneasel was weird, it went from brown with a green feather to back-blue with a red feather, and its shiny was NEON.

 

Umbreon's rings when it was shiny looked kinda purple which looked pretty nice actually, but I got to admit that the blue actually fits it a lot better.

 

None of those are shiny! Their old sprite colors look better than what they are now imo.

 

Sneasel was definitely a big change, since it was brown with icy blue feathers instead of the now-usual dark blue with red feathers.

 

Sneasel just weirded me out when I saw it.

 

Probably the most noticeable change in sprite coloring for is Spinarak going from being purpleish in Gold/Silver to being green in Crystal and all later games, as it's supposed to look. I never understood the rationale for Spinarak being purple, but now that I think about it, maybe it was initially supposed to be purple, but changed to green later on.

 

So we all know about Jynx's canon color change because of the controversy surrounding it's design (even though there is a historical/mythical reason in Japan for it to look that way), but it looks like there was actually an alternately colored sprite for Jynx in Crystal. I was looking through the list of sprites I've been using for my Nuzlocke journal and found these:



The one on the right looks like what you would think of when you think of the classic Jynx design, and the one on the left looks kind of like it's shiny form, but it's actual shiny form looks like this (Normal on left and shiny on right for comparison since they're so similar):



At first I was thinking the red and yellow Jynx was a recolor made to look more like the original, but even the animation is slightly different if you look closely at it. As it turns out, the red and yellow one is actually from the Japanese Crystal (and presumably gold and silver, since they use the pinkish-purple one for those too.) In all of the later versions, Jynx keeps the red and yellow coloration, with only the skin color changing to purple. So my theory is that it would have been too much for them to make an entirely new sprite with a different skin tone, so for the international releases of the games, they just darkened the shiny sprite ever so slightly. So if you ever catch a Jynx in the gen 2 games, congratulations, because you sort of have a shiny Pokémon.