Oh cool! If you haven't seen it, the "All About Color" deck that comes with Decker has some stuff about importing images that could help you have different effects e.g. using different palettes or using an external tool to dither it!
this is so good to know. on the one hand, i wish i'd known how to import images properly before I started; then again, I actually like the weird aesthetic my game has right now. but i'll definitely use these techniques on my NEXT Decker project. some of the images in this game are like Rorschach tests - you have to squint to figure out what you're looking at. :-)