I would suggest Fuji NPH 400 outdoor, and even NPZ 800 indoor.
The advantage is that being high sensitivity films they decrease a little bit contrast, which makes it easier to get correctly exposed both groom (black) and bride (white dress).
If you do not enlarge excesively, grain is not a big issue.
As Wilko said, avoid vivid colours. Else wedding guests have a tendency to become red-faced, especially after the first drinks and dancing. I would also consider B&W in addition which is much more forgiving in this respect.