I love this game! From the smooth transitions between scenes, the well-generated color palette each reset, the level selection, it's all great! The gameplay mechanic is easy to understand but leads to complex situations, and the level design is good as it teaches the mechanics in the early levels.
The music is great too, really adds to a relaxing atmosphere while you're thinking hard about the puzzles! The graphics are simple but matches really well with the game, so I'd say it's actually the right choice here :)
It's a solid game, can't wait for you to expand on this! :)