Use this procedure when you need to modify a control definition—for example, to change its icon image.
Copy the entire control definition from /usr/dt/appconfig/types/language/dtwm.fp to:
System-wide: /etc/dt/appconfig/types/language/name.fp
Personal: HomeDirectory/.dt/types/name.fp.
Edit the field you want to change. You can also add additional fields.
Save the file
Choose Restart Workspace Manager from the Workspace menu.