Have you seen the end of an adding machine tape where the paper turns a nice pink color to show that the roll is coming to an end? The brown color shows on the paper that is used for the inlays much like the pink color on the adding machine tape. I have seen several chips with the brown inlay on one side but have never seen it on both sides. In my opinion, these chips are defects that should have been pulled by quality control and are not valuable collectible error chips.