Yes, it turns out it is the body {background: #e2e2e2}.
However, I _did_ not understand how ‘adding’ a background color would tell me what that color was or which element was using it.
So what I did was install Color Detector, which displays the color hex code or the rgb values of whatever the cursor is on, and it showed #E2E2E2, so searching on that brought me to your suggested element, alchmyth.
And now I do understand what you were suggesting: if I changed that to, say, green, and cleared the cache and reloaded, I can see that that band of color changes to a solid green.
However, now what I need to understand or confirm is what is determining the width or height of its sections:
For the left and right is it a reverse application of the #content id and the #secondary id’s values?
And what is the element that is changing the content and secondary sections back to some value near absolute white?
This is confusing because the css seems to prefer less than absolute values of white for the content background – I’d like to now why, and if there’s a codex doc or other reference for that – and it appears to use a less than absolute value of black for the titles and text, so I’d also like to understand that.
Perhaps I need to make that last part another post?
Barry