Wonderful idea with the color palettes! It's one of those little things that let you customize/personalize your game and that does wonders for player interest (speaking from my own experience with the game) 😎
I have a feeling that some of the tiles are buggy (running on them causes sharp bobbing) - I would also add something to make the invisible tiles a little more obvious, or at least some NPC to comment on your death. Just as a reassurance that this was intentional.