I'd like to know what colors of food coloring you mix to get grey.?

white and black

If you know them all well enough that may be OK. If not, I would not expect them to do that. That is a little much don't you think? If you want to though, one idea is to request that if you want b/c it is like a wedding theme and think it would look nice in the pictures. I always heard though that you should be the only one wearing all white on your big day, but to me I did not care if my guest wore that. I did not care what they wore. I was just thankful that they took the time to be a part of my special day. Personally I think those colors are a little to neutral and dark. I think that some people want to dress colorful and wear their own style and choice of color. But do whatever you feel comfortable with. I would ask your close friends and family to get their opinion b/f doing it.