Hi everyone.
Unsatisfied with turning the css off, and losing my better preview, I digged a little deeper.
Just know that this is not a "problem" at all, in fact I like the editor to have the site background showing, as it helps me to style better the content. But if you change the background of the page, like me, and the change doesn't reflect on the editor, just change the way I did. I will look at other GK templates that can be "affected by the same problem" (as I remember, Black and White, a template I use a lot as base for my custom works, have the same problem. I will fix all my sites now).
It seems that your actual body background is controlled ultimately by style1.css. It overrides every other background body statement. But the JCE editor will use only the background stated on the template.css file, no matter what other files have ultimate control of the appearance on the frontend.
So, just change the background statement in line 20 of the template.css, and state your actual frontend background on the style1.css in line 22.
Important note: I have changed the entire background of this custom page I'm doing, removing the dual colors in favor of a unique background (and a different header bg, by the way). If you want to keep dual colors (because the body bg is showing through on the bottom-wrap div), just add a background statement to the corresponding div, or add another div under "bottom-wrap" and style it accordingly, your choice.
I hope this helps.
Jonathan Roza
www.zott.com.br