Pew Bows: Instead of using white, use ribbon with a printed fall theme, or a solid color edged in gold. You can hang ivy or garlands of leaves along the pews. Don't forget to use your fall theme on your programs too. In light of the fact that autumn is such a varied season, your only limit is your imagination. You can use any of the elements that you enjoy, and your wedding and reception should reflect them.
Enjoy those bold rich colors!