First impressions................I don't think it's colonial because it is set against what appears to be a very green hedge, maybe laurel but difficult to tell.
Not everyone is wearing a lapel badge and the people seated would appear to me to be 'special guests' otherwise why are there so few women and children?
The lapel badge is obviously relevant in some way; I suppose you have tried to enlarge it? Also it might help if you could post an enlargement of the 'special guests' - you never know, they could be famous people!
I would guess it is dated in the early 1900's, probably before 1920.
Jill