[AUCTeX] problem with non-white background in Emacs

[Darren Hoo]

Hi,
   I use auctex with xelatex which can only output pdf,I have
problem because I  use a non-white (black) background in Emacs
The color of the text is also black in the images created
I have tried  changing the color of the preview background
but it has no effect.

this is my settings:
 (setq preview-transparent-border 2.5)
 (setq preview-transparent-color  '(highlight :foreground))

for example  the output of $ \lnot \forall xP(x)  \exists x \lnot P(x) $
is as the image in the attachment.

pr1-1.png
Description: PNG image