Are you talking about the white mushrooms or the brown mushrooms? They are two different species. Destroying Angel will grow at the same time in the same place amongst many other varieties of mushrooms but they will never change color, all parts of them will stay pure white.Sounds like a field variety of Agaricus, you can get a lot closer to sure by taking a spore print. You can do this by putting the mushroom in a very still air area (top of the fridge) with the gill sides down on a piece of paper and giving it a night. If you need further help identifying after you've taken a spore print see if you can get a clear picture of the gills and how they are attached to the stem.
Good luck identifying!