Yes. This article describes a recommended method, as well as two others.
The recommended method
1. Create a file called ".X11" in the home directory of the user. Ensure that the ".X11" file is executable. The contents of the ".X11" file:
X -screen 0 -depth 8
2. Log on, selecting an X Window session at the login dialog.
Here are two other methods
1. Modify the /usr/bin/X11/X file and insert before the $* in the startup entry:
-screen 0 -depth 8
2. Start X11 at the command line in color with the command:
/usr/bin/X11/X -screen 0 -depth 8