I like both, the symmetry is nice, but I prefer the colour version as I feel B+W generally works better with more minimalist compositions, and while this is not a busy composition, there is a bit going on
Color for me. The mono version is too dark. Maybe processing this differently during conversion would help lift the shadows some.
The green reflection in the shadows of the color version saves the shot for me. This is gone in the mono version.
Both look good, each in different way, with different mood.