<p>Definitely not a suit. I didn’t see a single boy wearing one in all our trips. None of the AOs or teachers at prep schools wear suits, so it would seem very out of place for a boy to be wearing a suit. It’s just the wrong vibe. No reason it needs to be khakis if you really hate them. A navy blazer and gray dress trousers would be fine, or I suppose even nice cords and tweed blazer (though I know my son wouldn’t be caught dead in cords).
Personally, I’d argue with ThacherParent that a coat and tie seems a bit overdone at a school that has a very casual dress code. This is obviously totally a matter of personal opinion, so there really is no right or wrong, but to me a coat and tie in that circumstance reads as though you don’t know much about that school.</p>