Never thought about the reds, I guess due to them being not overly rare considering and multiple examples of each (I think) this was a deliberate change similar to the apple greens.
A Br Lenox and Black Lenox can be found with the same front (Cobb off, Jordan, Lajoie etc) but not with the Hindus or apples. I feel this brown batch was a test or wrong color put on one/two or sheets and that's it.
I also am a novice to these types of things