I scanned these 3 Scott 78 variety stamps side-by-side. To my eyes the one on the left is grey as I can't pick up any lilac tones in it at all so I'm guessing 78b. The middle one I think has a very light lilac tinge to it, so a 78 or possibly a 78a. But I am at a loss when it comes to the third. I can make out no lilac in it at all. So, please help. How should I classify it? Is there such a thing as a very dark grey?
I've seen the color charts for these in earlier posts so I know there is some real expertise here on this issue!