Could we get a USE flag enabling support for 24-bit colours, please? Unfortunately this still requires a third-party patch to be applied, that said I have been running urxvt with the patch from https://github.com/da-x/rxvt-unicode/tree/v9.22-with-24bit-color for a few weeks now and everything seems to be in order.
See also [1]. Please send your patches upstream. [1] http://cvs.schmorp.de/rxvt-unicode/doc/rxvt.7.html#I_am_using_Debian_GNU_Linux_and_have