Antonio, I am so glad you posted this question here. I have been wondering if this might be a good forum for people to discuss their photos when they wanted constructive feedback and you've just answered me.
I like your image of the shrine and icon in the background with the rose in the foreground best in black and white. I think it allows me to see the connections between the two more readily without the distraction of strong reds and greens in front (a candle?) of the icon of Mary (I'm assuming it is Mary). Additionally, the rough texture of the stones, the shrine...all being in black and white have more cohesion and yet still allows the emphasis on that delicate "rose" which I think (even for those who don't know the historic iconography of the Christian religion as it evolved due to Latin Western cultures, and thus don't know that the rose has always represented Mary, Jesus's mother) can readily understand the rose as a representation of life, hope or at least beauty.
That's my early morning, first cup of coffee, art history, photographic response, and I'm sticking to it.
Antonio, you know it might well be interesting, since I believe you do have the software abilities, to isolate the rose and add the very slightest, wash of pink color to see if you'd like it that way. I don't know how it would look in this case but I think John's suggestion could be worth exploring. I also would be interested to see if Will's suggestion of "sharpening" or adding a bit more "clarity" - not sure of the right terms - to the black and white might make it more powerful.
Thanks so much for starting this thread. When I first saw this new thread and didn't know who'd started it, I thought it might be Ferry's since I'd just seen two versions of one of his photos via Flickr and his blog, one version in color which he's posted here as well but black and white on his blog. I do think it can be helpful to post two versions to get feedback or as I call it to get out of our digital darkrooms and see our images out in the open. So thanks for starting the beginning of a possible trend here.
P.S. Will, I like yours both in black and white and in color too. They do different things to me. I appreciate them both.