Just configure your window the way you want it and then choose the Shell->Use Settings as Default command. There's no need to do anything from the command line.
From your comment, I understand that you want to be able to set the preferences for Terminal from a script as part of configuring a machine automatically. The easiest way to do that is probably to configure Terminal the way you want, and then make a copy of
If you then copy that file to the target machine's
it'll become the default Terminal preferences for every user on that machine. Or, you can copy it to:
to set the Terminal preferences just for user username.
You probably already know at least some of this. I know this answer skirts the question of how to do the equivalent thing with the
defaults command, but if you do:
% defaults read com.apple.Terminal
you'll see that the value for the "Window Settings" key is a fairly complex dictionary that's going to be difficult to manipulate with
defaults. I think it'll be much safer to let Terminal write the settings, and for you to simply copy the entire settings file.