Upload & Sell: Off
I happen to be looking at these on an uncalibrated office monitor. On this screen, the skin tones of the two color versions look nearly identical. The middle image appears somewhat less sharp, and the water and sky are obviously more blue. In the leftmost (SOOC) image, the skin tones appear very slightly more orange/red -- that's the only skin-tone difference I can see here. Neither version looks inappropriate on this monitor -- they both look good as far as the skin tones go.
The blues in the middle image, however, appear much more natural and pleasing, at least on this screen.
Finally, on this screen, the B&W version appears a bit over-exposed (e.g., shirts appear almost completely blown out) and therefore the skin tones seem a bit bright and low-contrast. Again, this is on an uncalibrated crap-heap monitor. You know, the kind your clients are using.