I don’t want to reveal anything major at risk of being struck by the Nintendo Ninjas, but one thing I will reveal is that there are alternate patterns for every Pokemon, similar to Magikarp: Jump.
These don’t change colour, and mostly consist of stripes, spots, etc., being placed on the Pokemon. They could be considered similar to shinies, but, much less rare.
There are three for every Pokemon, meaning a lot to do for you completionists out there.
You may not believe me, and that’s fine, you’ll see when the games release.