[Tex/LaTex] LaTeX equation that has white text on a transparent background

Question

I would like to create a LaTeX equation that has white text on a transparent background, so that I can use it on an array of dark backgrounds in PowerPoint/Keynote.

\color{white}
\nopagecolor
\begin{equation}
 V_{\rm eff}(k) = \int d^3r \; \left [ n( { \bm{r} })P(k) \over  1+n(\bm{r})P(k)\right]^2
\end{equation}

But doesn't work.
Any thoughts?

Answer 1

With the standalone documentclass one can create a document which just contains an equation and (in case PP/keynote cannot directly import a pdf) convert it into a .png with transparent background:

\documentclass[margin=6.626mm,convert]{standalone}

\usepackage{xcolor}

\begin{document}
\color{white}
$\displaystyle
M87 = \mathrm{cool}
$
\end{document}

(needs to be compiled with shell-escape enabled)

<- Hard to see here, but this produces an image with transparent background and white font