I can launch an xterm from the command line (or a program, via a system call) like so:
/usr/X11/bin/xterm -fg SkyBlue -bg black -e myscript
You can also go into terminal GUI, completely configure the options to your heart's content, and export them to a ".terminal" file, and/or group the configurations into a Window Group and export that to a terminal file "myGroup.terminal". Then
open myGroup.terminal
will open the terminal(s) at once, with all your settings and startup commands as configured.