Thanks- had to take a crack at it. You nailed the blue in-hand look... my camera doesn’t capture blue toning very well for some reason.
I have a feeling that it was net graded due to questionable color. I think the grade is a bit tight, but I don’t necessarily disagree with it. The color will give it a nice premium over a generic 64 brown, so the number is really less significant than the fact that it received a straight grade.
I think you are probably right, though toned copper can often look very different in hand than it does in photos. This is a coin I would need to see in hand before saying it was undergraded.