Watched this video a while back and it talks about brown color back however it is not exactly Brown OM. It does seem like there are diff shades of brown in Lenox but the differences are very very slight. It could be due to the reflection from the graded case.
https://www.youtube.com/watch?v=V2TJXHnybEE
That "Brown" OM back being asked recently appears to be black to me.