My top colour picks for a Fall wedding are gold, burnt orange/red, and brown hues.
Here are some fall inspired wedding ideas!
At one wedding I assisted at, the bride and groom chose to cut and serve pumpkin pies instead of a traditional wedding cake (or serve mini apple and pumpkin pies)
I wouldn't suggest a Halloween-themed wedding but Halloween-inspired candy like candy/caramel apples or candy corn is always fun
Fall leaves lining your centrepieces (Make sure you gather them on the morning of your wedding so they don't get dry and wrinkled)
Pumpkins are place cards
Fall foilage boutonnieres (acorns, dried leaves and orange/yellow ribbon)

Source: Martha Stewart Weddings