unknown bird in Long Lake Michigan......chocolate brown head and neck, charcoal body and tail, ivory wings, top and bottom
That's a very interesting set of colors.  Unfortunately nothing springs out at me, although I can think of a couple of birds that might sort of (maybe) match.
First, common pigeons come in all sorts of colors and patterns, and it's possible that yours is one.  On the other hand, common pigeons tend to be very familiar to most of us, so I don't think you'd be asking about that.
Second, there is a tern that is moving through the area about this time of year, that might fit:  Black Terns can have a lighter wing.
Here's a link and a representative photo:
 https://www.allaboutbirds.org/guide/Black_Tern/overview


There is another, even better possibility, if your bird is ternish:
The White-winged Tern (formerly White-winged Black Tern) is an uncommon late-summer wanderer through much of the region.  Here is a link and a representative photo:
https://avibirds.com/white-winged-tern/