'GIMPed up' Naki Ball

This is a version of my previous drawing after using GIMP (for the first time actually)

If you would like an explanation of the character, just see my previous B&W drawing.

Also, I would love any critique on how to improve any part of my work (because I know I have some major issues). I am a BEGINNER GIMP user, so if you would also like to provide a link to a tutorial you think would be helpful for me, it would be much appreciated.

Thanks!