I haven't checked out the demo for the main game of Colorful yet, but I remember reading some good things about it and thinking the art I saw looked beautiful :3 Spooky edition is even more my cup of tea, haha.
I haven't had a chance to play through all of it yet since it's pretty long, but from what I've seen so far, it's so polished and lovely to look at :3 All of the art is absolutely gorgeous! I'm loving the matching UI so much too.