Currently BOINC manager uses the 48x48 icon from /usr/share/pixmaps/boinc.png, which looks quite ugly when using GNOME, for example. There are better icons from http://boinc.berkeley.edu/logo.php. Please also see the original upstream bug report: https://github.com/BOINC/boinc/issues/1603
That is a nice idea, thank you very much. I'll see what I find, but it has to wait until next week, as I am very busy at the moment.
Please see my commit here: https://github.com/gentoo/gentoo/pull/2768/commits/fe432c1744bf01eb2cabfad94f43ad709b743a61 Are these icons in order?
The icon generated by the new -r1 ebuilds should look much better. Thank you very much for your suggestion!