Mark Abene says on linux-pmac:
 
Look at the man page for the "setterm" command.  It will let you adjust the
text console colors, among other things.
 
jonh@cs.dartmouth.edu
 
 
This is a nice thing to put in your /etc/profile file, btw.
 
kenlu@mit.edu
 
 
If it's the blue-background to which you're objecting, there's a better
way to fix it: change the source of the problem--the kernel.  It's not
hard, and I'm offering pre-compiled binaries for the uninitated or 
kernel-hacking-wary.
 
See http://www.chad.org/about/MkL/blue/  for (somewhat limited) information
about what to change, and the kernel binaries.

                             Chad <cmiller@surfsouth.com>
 
 
In MkLinux, you can also set a boot parameter in /mach_servers/bootstrap.conf.
If your previous bootstrap.conf file looked like this:

  -w default_pager /dev/boot_device/mach_servers/default_pager
  -k -S 524288000 startup /dev/boot_device/mach_servers/vmlinux

add a "-c" switch to set "environment variables" for vmlinux when it starts.

  -w default_pager /dev/boot_device/mach_servers/default_pager
  -k -S 524288000 startup /dev/boot_device/mach_servers/vmlinux -c "root=/dev/sdb9 regular_vc_colors"

Note: YOU MUST SPECIFY YOUR ROOT DEVICE WHEN USING "-c"!

Info courtesy Tom Rini <tmrini@ntplx.net> on the mklinux-setup mail list.

ddkilzer@earthlink.net

Setterm sometimes doesn't work if your $TERM is vt220. 
However, i have had good luck with
$ setterm -term linux -background cyan

This one is great- goto a terminal program and type;
gedit .bashrc {return}
Under where it says 'alias', the last entry add this line...
alias ls='ls -a --color=yes'
Save the changed file and exit the terminal. Then launch a new terminal and whoa! Pretty cool huh?