Hi Marius, sorry for this way to late answer, I totally missed this bug.
* xfishtank is now on sourceforge: https://sourceforge.net/projects/xfishtank/ * On my system: Linux piccolo 6.1.0-23-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.99-1 (2024-07-15) x86_64 GNU/Linux running in xmonad 0.17.1-1, xfishtank 3.2.2 runs without problems, all buttons are functioning. * The background color is valid in combination with xscreensaver, see the man page. * The licence is MIT. Thanks for your bug report, Regards, Willem