[AUCTeX] adding background for transparent images in preview-latex

[Tamas Papp]

Hi,

I am using a low-contrast light-on-dark color scheme (Solarized-dark)
in Emacs.  In preview-latex, the preview for some PDF images (dark
lines on transparent background) is very hard to see (screenshot:
[1]).  I understand that this is not the fault of preview-latex, but I
was wondering if it was possible to render these images on a white (or
custom color, eg the foreground color) background.

I tried reading the archives, fiddling with preview-transparent-color
(currently set to NIL), even setting

(setq preview-dvipng-command
       "dvipng -bg white -picky -noghostscript %d -o \"%m/prev%%03d.png\"")

but none of these changed anything.  I was wondering whether, for
example, GS or dvipng can be made to render on a white background,
preferably only for PDF files, but any suggestions (also emacs code
snippets) would be appreciated.  I am using emacs-version 24.0.93.1,
preview-latex 11.86.

Best,

Tamas

[1] http://www.zimagez.com/zimage/screenshot-02082012-042751pm.php