Changing color depth in Ubuntu 9.10

[edwardp-KK0ffGbhmjU at public.gmane.org (edwardp-KK0ffGbhmjU at public.gmane.org)]

>
> On my (fresh) install of Karmic, xorg.conf exists, and about the only thing
> in it is a setting for Screen ->  DefaultDepth ->  24.
>    

I tried "sudo find xorg.conf" and it indicated the file was not found, 
assuming that is the correct command to find a file.  It is not in 
/etc/X11/ as with other distros.  This is with a new install of 9.10.

It is that 24 that I want to change, to 16.

I am trying to solve a Flash-related audio problem, which was also 
present and fixed in Windows on the same system, when I changed the 
Windows color setting from 32-bit to 16-bit.