[SS Tim]

Based on the fact the seats are a single color and match the headliner and visors, I'd be inclined to make the carpet darker to bring up detail.

One color can work against you as anyone with a medium blue with blue trim truck can tell you.

Since the body color contrasts well with the vinyl a matching carpet would work.

However, IMHO, I still feel it will look best with the fourth/bottom choice or the third/one up. Especially if you are considering kick panel and or lower door carpet too.