I don't normally sprite Pokémon anymore but here are some Final Fantasy styled battle sprites.
I'm not super committed to the idea of making every single Pokemon this way, so the maximum limit I'm going to go to is the Kanto region. I might do Johto ones if the fancy strikes me, but these sprites are far from a priority.
Also, they're on a black background because that's how final fantasy on the NES handled the battle sprites, and why the battle screen was always black to allow for more colors per image, allowing the background to act as the outlines where it needed to.
That's also why the BG was white on the GBC, to make that white look like a 4th color on sprites. But you can tell it wasn't actually one when the trainer back sprite crossed over the wild Pokemon or other Trainers, 'cause you could see right through the white spots.
With that said, the FF games made more use of colors than just the 3 + black. Because the enemies were composed of 8x8 minitiles, they were able to let some 8x8 minitiles be of a different palette, to make the overall sprite look like it uses more colors.
http://www.spriters-resource.com/nes/ff3/sheet/31768/
Just keep that in mind if you're going to continue...right now, it doesn't look like these three need that extra push, but that fact can allow you to use more colors as long as you're mindful of what the 8x8 minitiles are.
The only thing I'd say about what's there now is that Squirtle's head could use a shine.
Actually, due to the
attribute clash of the NES, the system only has 16x16 attributes, not 8x8 attributes. The only exception are games that used the MMC5 chip, but that chip was only used in a dozen or so Japan-only releases because it was so expensive to produce.
(A screenshot from
Mother: 25th Anniversary Edition, a MOTHER 1 ROM hack I did a while ago)
But of course, sprites in NES games can have 8x8 attributes. And if you overlay sprites onto tiles, you can achieve more colors. Oh, and the GBC used 8x8 attributes, which might be what you were thinking of.
I like how you used the exact same palette for Squirtle and Wartortle but flipped which color was the most prominent in order to show the difference in their brightness.
Very clever.
I wonder if Charizard could be done the same way using Charmander's palette?