in /etc/X11/xdm/Xsession 4th line is :
xsetroot -solid #356390
I do not know what does this mean but it always gives a
syntax error , every time I try to log in , with the
following message:

usage: xsetroot [options]
  where options are:
  -display <display>   or   -d <display>
  -fg <color>   or   -foreground <color>
  -bg <color>   or   -background <color>
  -rv   or   -reverse
  -help
  -def   or   -default
  -name <string>
  -cursor <cursor file> <mask file>
  -cursor_name <cursor-font name>
  -solid <color>
  -gray   or   -grey
  -bitmap <filename>
  -mod <x> <y>
What is the problem ?