This image has always been a no brainer for me. The colour makes it and always has. The colour seems to place things better, making the lighter parts sit well against the darker.
The mono version is fine I guess, but the image needs, I feel, the red contrasting with the white. I suppose I could darken the red in the mono image, effectively turning it black, but the warmth does something that a darker grey does not and the skin tones would be lost. I do like the lightness the mono image has, the way it looks more open and balanced, but not in comparison to the colour one. To be honest, if the mono was the only one I had, the image would have been seen as "B" grade at best and probably forgotten about, but the colour adds something that I really like. I think it may be the way the early Olympus sensors (EM5, EPM2, Pen 5) often render a nostalgic look to the colour, deep and contrasty. I see memories or Fred Herzog and Saul Leiter, the true Kodachrome look. I feel images like the one above (assuming they could cut it compositionally) could slide into a page of one of their books, unnoticed.
If the colour image was composed of say dark blues or just looked cold, the mono image would most likely look better.
Something I really appreciate about the OMD and Pen mini 2 cameras I have is, they look a lot like my memories of film. The mono can look like a "hot" S-curve film like FP4/XP2 with it's light and glowing whites, smooth mid tones and deep blacks (like above), or "cold" S-curve like Tri-X, with more grit in the mid tones and detailed, gentle high lights and shadows. The colour is Kodak like (again, above), but with plenty of Fuji colour (Reala) built in for taste. I also see AGFA print film looks sometimes (Portra in particular). Simply put, they often don't look as digital as some files.