add option to change bgcolor for gpl-term function

settings/org-settings.el

@@ -861,10 +861,11 @@ See also: http://www.gnuplot.info/docs_5.2/Gnuplot_5.2.pdf#section*.519
     (concat filename (by-backend (latex ".tikz") (article-latex ".tikz") (t ".svg")) )
     ;;(by-backend (latex "") (t (concat filename ".svg")))
     )
-  (defun gpl-term (lsize osize)
+  (defun gpl-term (lsize osize &optional bg)
     "\
 LSIZE: latex export size
 OSIZE: other export size
+BG: optional argument, e.g.: \"ffffff\", defaults to \"11000000\".
 
 returns: term settings for the org src gnuplot header :term
 - for LaTeX export it is set to: lua tikz size LSIZE color colortext
@@ -873,10 +874,12 @@ returns: term settings for the org src gnuplot header :term
 usage: #+HEADER: :term (gpl-term \"15cm,12cm\" \"380,300\")
 "
     (concat
-     ;;(by-backend (latex "epslatex size ") (t "svg size "))
      (by-backend (latex "lua tikz size ") (article-latex "lua tikz size ") (t "svg size "))
      (by-backend (latex lsize) (article-latex lsize) (t osize))
-     (by-backend (latex " color") (article-latex " color") (t " mouse standalone background '#11000000'"))))
+     (by-backend
+      (latex " color")
+      (article-latex " color")
+      (t (concat " mouse standalone background '" (or bg "#11000000") "'")))))
   )
 
 (use-package ob-latex