[ale] Xdm startup question

[John M. Mills]

I am running RH4.2 and XFree86-3.3.1.

I would like to change the default color depth when my system starts at
runlevel 5, running 'xdm'.  If I start X manually, I could do something
like:
% startx -- -bpp 16

How do I tell 'init' or 'xdm' to start with an option like this?

TIA - jmm

  John M. Mills, Senior Research Engineer -- john.mills at gtri.gatech.edu
  Georgia Tech Research Institute, Georgia Tech, Atlanta, GA 30332-0834
        Phone contacts: 404.894.0151 (voice), 404.894.6285 (FAX)
         "The cardinal virtues of a programmer are Laziness,
            Impatience, and Hubris." -- attr. Larry Wall