this version uses the default image files for piwik, which currently have a white background - so many images will be white on dark. on my own installation i have replaced these images with dark variants - i might upload them somewhere in the future.

INSTALL NOTES:

you need to install the stylish add-on for firefox or whichever browser you use..
then install the piwik userstyle from this site via the stylish add-on.
you also then need to edit the userstyle so that it includes the url location of your own piwik installation.

REPLACE THE LINE:
@-moz-document domain("piwik.yourdomain.com")
TO INCLUDE THE LOCATION OF YOUR PIWIK INSTALLATION, E.G.:

@-moz-document domain("stats.hatsformonkeys.com")