If you don't mind some crit, I think you're only problem is that you put your lines on the background. Its always a good idea to put your lines on a separate layer so that people can color underneath them. Otherwise they end up accidentally irrasing the the lines by coloring over them. I love your different layers though.

Oh! and to change the name of the layers you double click on them and then you can rename them. I mean double click the name, not just the box.

Hope that helps! I love the general shape though.
