Problem displaying 88 colors when running screen under rxvt-unicode (urxvt)

[Serge Koksharov]

  Hi,

I use rxvt-unicode (urxvt) v5.3 terminal which supports 88 colors . When
I run color test 88colors2.pl (you can find it in XTerm source code
tarball), color cubes looks correctly. But when I run screen v4.0.2 (of
course compiled with 256 colors support) under urxvt, and launch this
test again, color cubes have wrong, messed up swamp-green looking
colors. It looks like screen runs under 256 color mode, because "echo -e
\"\033[48;5;${color}m\"" command, where 'color' variable is in range
from 232 to 256 generate grayscale colors. So, how can I
tell screen what underlying terminal have 88, _not_the_256_ colors. I
can't find this neither in manpage (which unfortunately have _NOTHING_
about using screen in 88/256 colors mode) nor in screen-users mailing
list archives. I already spent buckload of time, trying to get it work,
but unfortunately I'm not skilled enough to find the answer in screen
source code. So any help is greatly appreciated. Thank you in advance.

P.S. I'm not subscribed to mailing list, so if it's not hard to you,
please CC your answers to me.
P.S.2 Last version was released more than 2 years ago. Why? Nothing to
improve?

Sincerely yours, Serge