screen on 256 color xterm

[Dr. Johannes Zellner]

Hello,

how do I get 256 colors in screen running in an 256 enabled xterm?
I tried to create a terminfo entry like this:

screen-256color|screen on xterm with 256 colors,
        ccc,
        colors#256,
        pairs#32767,
        
initc=\E]4;%p1%d;rgb\:%p2%{255}%*%{1000}%/%2.2X/%p3%{255}%*%{1000}%/%2.2X/%p4%{255}%*%{1000}%/%2.2X\E\\,
        setab=\E[48;5;%p1%dm,
        setaf=\E[38;5;%p1%dm,
        setb=\E[48;5;%p1%dm,
        setf=\E[38;5;%p1%dm,
        use=screen-bce,

(stolen from the xterm terminfo).

But the colors are not correct. Especially the colors of the
6 x 6 x 6 color cube (colors 16 - 231) seem to be somehow "rounded"
so that the color shades are lost.

To illustrate this a bit I put the correct xterm colors at
    http://www.zellner.org/screen/xterm.png
and the wrong screen colors at
    http://www.zellner.org/screen/screen.png
The two images also show the corresponding color number and were
generated by the python script http://www.zellner.org/screen/colors.py

Any help much appreciated.

-- 
Johannes