I would also like to add my input (current Williams student here). Regarding @abstudent44 's comment, I am unsure if being a part of the NESCAC means having “much closer” interactions with the other. Do you mean sports-wise, as in competitions and whatnot? Then yes, there might be more interactions between the NESCAC schools. Otherwise, though, I am unsure what you mean, and don’t think there is a particular special bond felt across the NESCAC schools. I would also disagree that being a part of the NESCAC offers you an edge when it comes to finding employment because, after all, it’s mostly the student who makes up the fit and case for why they should get a job, not the school’s name brand that does so.
Going back to the original poster’s points, I am honestly not sure what I would do in your shoes. My first advice would be to visit the two schools (since a visit means so much more than advice and comments you receive online), but since you can’t, I would really consider the differences between the two schools and try to see which is more appealing to you. I am not particularly an expert on either school, but I do know that Haverford is a part of the Quaker Consortium which allows you to take classes at participating schools such as Swarthmore, UPENN, etc, if that is something that intrigues you. I am honestly not sure about Colby (but that’s why we have the internet!).
Good luck. Deciding where to go can be a stressful process–especially when you can’t visit–but at least it will be over soon, right?