Cool shot, but to be completely frank I'm not too fond of the selective coloring - and if it is going to be used I'd love the rest of the shot to be much higher contrast.
My opinion is selective coloring should be relatively subtle almost unnoticeable but it seems to work a lot better with children the way it has been done here. I actually clicked on this thread on a whim I usually don't like to comment on shots of children as they tend to be a sensitive subject for most but I like this one quite a bit.
He is cute, but the picture looks really under-exposed to me. Maybe that was your intention though? As far as the coloring, in this case, I would go all color or all B&W, but not selective. It takes away more than adds to me.