My thoughts on the picture are this: We have a huge group. I have been told by a couple of fantastic (expensive) professional photographers that for pictures like this people should all wear the same color (exactly the same color). I tend to agree. I think with more than one color, you look at the clothes and not the people. My vote would be one color scheme. Maybe dark brown and khakis or jeans. Black and khaki or jeans. White and khaki or jeans. I like simple clothes, simple colors = Look at the people. That's my input.