Final Fantasy Hacktics

I am aware that there are about 4 different variations of each generic sprite - one per faction. Blue, Red, Green, probably one I'm missing.

However, in Shishi, after this, there's a bunch of versions that are just black outlines - are these 'spare slots' in the game that just aren't used, or does Shishi always display 9 (or 10, can't remember which) versions of sprites regardless of the game?

Secondly, and more importantly, can the game (or Shishi) tell that they all look the exact same, aside from colours? If not, I was wondering if it's possible to have each faction have wholly different sprites (as long as they don't hit the colour restrictions) as opposed to different colours - for example, the player's black mages could be Lulu, and random enemy generics could be the standard black mage. Is this possible?

If I remember well (can't check right now) you can give up to 8 different palettes for any given sprite. The game uses 4 for all sprites.

Second, yes, it can. If you ever wanted to make such a change between the palettes, you would have to be a high-level master of art, being able to form two units with one outline, I can't really explain but that how it would be done... One pixel remains the same - it just changes colors, and you have only 16.

Oh, so all different versions have to have the same outline?

Yes, unless you are a master of spriting. I can't quite explain it - try it to understand.

Ah well. I'll see if I can get by adhering to the way it's done in normal.

Assume it's a NO, but it is possible, if the main sprite has less than 16 colors.
(for the second)

The palettes or what you call factions is dependent solely on the pixels of the sprite.
I think*