Hey Kizu, I like your idea. I find it really nice when we have unusual characters in mundane situations.
This is my fist critique here so I hope it helps:
Let me tell things I think you have going for you:
-I really like the structure of the standing character.
-You are shifting hue a bit between each color value.
-You managed to keep the focus on the sleeping witch, that blue on the hat is well placed.
Here are some things that i would've done in a different way.
Hope it helps