Those are all very valid actually! (Not like u need my acceptance lol) My friend who plays S4 with me (since 2007-8 XD) said something very VEEERY similar to whats being said here, yesterday! That would be a lot of work tho! Im guessing they use Paint.net. (From what I can see anyway.) To do it could be simplified with default pallets like how the pieces used to be regularly on S4 Back in the gap with multiple textures. And such.
(I'd change the textures of MY Specific set myself, but I am NOT tryna get banned!! LMAO!!!! XDXDXDXD)