In the old days, all X11 applications would take standard command-line arguments to specify things like foreground/background color. Is there a way to do that today for GTK applications? In particular I'm interested in controlling the colors of zenity dialogs.
I use Xfce with Fedora 20, if that matters.
If it can't be done on command line, I'm open to hearing about alternatives. I don't know how to do this at all (even though command line would be preferable).