Calibrating Color From Tape Footage, Setup?

Hello!

I am working for the online marketing division of a studio and we have a modest but growing video department. We're now hitting the point where we will need to be able to deliver color-accurate movie trailers on the web. So, I'm charged with diving into the waters of the uber-technical and finding solutions that even an entry-level video assistant could understand if he were charged to color correct footage we receive.

We have a setup where a bunch of decks go through an analog switcher into a ADVC-500, which connects to our machines via firewire.

We recently captured a trailer from a DigiBeta tape (using the analog component connection), and the feedback we received from the higher-ups was that the colors looked "dull." I used the color bars on the tape and the vectorscope in FCP to color correct the footage, and it looked much better, but it still wasn't quite as good as the encoded clip a post house was able to deliver to us.

My question is, is there any way to calibrate our equipment so that it will be accurate every time, or will it always be on a tape-by-tape basis? Are there settings on the deck that determine how the color comes out? If we were to use the digital I/O on the deck and got a card that would allow us to capture uncompressed digital video from the DigiBeta tape, would that guarantee that the color would show up exactly as it was laid down to the tape or would we still need to color correct to make it match?

How to the large post houses handle color from tapes coming in when they encode it for web?

Thank you for your help!!!

Nick