That amp is the latest design. It may be that the documentation was updated sometime after you received your original subwoofer and that it hasn't been updated to reflect the most recent changes. That would explain the references to wire colors on both the amp and woofer being incorrect.

At this point, wouldn't you rather have an amp with the most recent upgrades included (perhaps done on an older amp, hence the refurb "feel" your're referring to) than a "new" one that's been in a box and might not have the most recent changes?