I seem to remember in the distant past when I used to drink that sour mash stuff that there were two kinds.
Black and green. Never did find out the difference.
Green is lower quality!
"Both are made from the same ingredients; the difference is determined by professional tasters who determine which of the batches will be graded out as worthy of being labelled with the prestigious black label, the rest being sold under the green label."
There's also Gentleman Jack which is charcoal filtered or some such and various Single Barrel things.