@Snorkledorf: That's a valid concern. I might end up making that configurable, in fact
.
In the meantime, you can edit the
linkss/bin/cover-extract script (with an UNIX friendly text editor, since this is a shell script, and all hell will break loose if it's not using *nix line endings):
Look for
-background white @ L116, and change it to
-background black.