All the illusion games are very moddable and generally have large ecosystems of content and mod plugins etc.
Within the modder content there's almost certain to be the type of stuff you want (and much much more), and or a guide on unpacking the game assets and editing textures yourself.
You just need to find the communities where it all gathers, like hongfire used to be back in the day - although the time for koikatsu being popular is a bit past now so there might be significant bit-rot. As far as I know F95 is not a big player in the illusion games scene.
