Capitalization in a series

I think this is purely a style preference, but I want to confirm (and settle a debate amongst colleagues). In general, is it better to use:

Antioch, Oberlin, and Boston Colleges.

-or-

Antioch, Oberlin, and Boston colleges.

On another forum, I found that the AP would choose the latter in the case of lists of things like rivers and mountain ranges -- I assume the same goes for lists of things like academic institutions. I can't find a style guide that advises the former, but it's nearly impossible to find results on Google that answer the question (I'm not even sure what to put into the query..."capitalization of a series of proper nouns" doesn't do it).

Thank you in advance.

As a former Antiochian :) I wouldn't capitalize "colleges", it is not a name. Only exception: If this were a title, then I would capitalize it. (At least, that's how I've learned it.)

Yale University has 'U' capitalized as it is part of its name similarly if 'Boston Colleges' is supposed to be the name of a group of colleges then I'd capitalize the 'C' otherwise I wouldn't.