I've decided I like this better without the outlines in the background. I love the ease with which you can apply tones in Manga Studio and I am having fun learning how to use them.
There is a precedent for this style of course (isn't there always?). I was watching Pokemon today (not much on TV at that time of the morning while I'm having a cuppa) and noticed this is how they do it. The characters have outlines and the backgrounds don't. Although my style of drawing is quite different and limited to black and white, for this one at least.
I'm finding it quite addictive.