By default, Ultra 5's with the PGX24 graphics card start up in 8-bit color
depth mode.  To change the color depth to 24 bits, do the following:

1. Install the patch 103792-14 or later if you are running Solaris 2.5.1 11/97
   Install the patch 105362-13 or later if you are running Solaris 2.6 5/98

2. Reboot the machine after installing the patch above.

3. Login as root and run the following command:                  

Kill dtlogin

# /usr/bin/ps -ef|/usr/bin/grep -v grep |/usr/bin/grep -v ksh|/usr/bin/grep dtlogin| /usr/bin/awk '{print $2}'|xargs kill -9

     #m64config -depth 24                  

Check your settings:

# m64config -prconf |grep Current

Current resolution setting: 1152x900x76

Current depth: 24

You cannot go higher than 1152x900 in 24 bit mode on the PGX24 framebuffer.

     # /usr/dt/bin/dtlogin -daemon; exit
   -- or reboot the system.                  

The above steps are needed so that Openwindows/CDE Xsun server does not write over the m64config settings. You cannot effectively use the m64config command while Xsun is running on the system.

4. If you are in CDE or Openwindows, please exit now and login again
   so the depth changes take place. 

5. Now run /usr/openwin/bin/xwininfo and select the background. You should
   see the depth set to 24 if the Xsun was started in 24 bit mode in 
   /etc/dt/config/Xservers (defdepth 24). If it was set to 8 bit mode (defdepth 8),
   you will see that this file's settings overwrite the m64config settings.
   In other words, in CDE/Openwindows you will see:                  

# m64config -prconf |grep Current

Current resolution setting: 1152x900x76

Current depth: 8

Also, see SRDB 18439 (why doesn't my PGX+ card keep it's 24-bit color depth
setting?).