
I think the color may detract from the image in these underground shots -- the rock is fairly uniform in color, and the major color differentiation is due to color casts from the artificial lighting.

I usually strongly prefer color over B/W shots, but I think in this case, the B/W is a lot stronger.
The conversion was done with Nik Silver Efex Pro 2 -- Preset: High Structure (Harsh). Using the 15 day trial now -- going through older photos now and trying to see if I like my favorite shots in B/W enough to plunk down $200 for it.