These two seem to be different shades, but as I look on Stampworld I am unable to distinguish which they are. I believe that the postmarks give hints to identification, but I am not knowledgeable enough to use them to help identify them. Any help would be appreciated.
The different shades are priced VERY differently! It would be great if one of them is Scott #36a (purple, 1875), but I doubt that I could possibly be that lucky!