We really aren't picky about what our guests wear, but we are playing into the Friday the 13th in October kind of theme - so dark/fall/jewel toned colors would be great! No requirement for attire though - formal to semi formal works! Just be sure to bring something warm to wear in the evening, or even during the day as we just never know what it's going to be like in October. And the event is on grass, so I would suggest no stiletto heels!