You guys bring up interesting points. I have almost no experience using lather on a classic barber hone and ever so little more with Arkansas stones. I am now using a classic barber hone, a no name combo, on some razors. The hone is black and reddish brown. I have two of them. I tried lapping the blacks sides against each other and it was really inky! Just like a black ink.
But the really good part is that the black side is working really well as a substitute for a Japanese 4000 waterstone. Frankly, I will be using the black side from now on. When I purchase a Norton 4000 ( I have the 8000) I will compare them. The reddish brown side is not as fine as the 8000 Norton. Possibly a 5000-6000. Perhaps later I will try some lather on that side and see if that results in a finer edge.