The first two are very appealing to me, I think because they remind me strongly of ink-and-wash paintings. I think the blue coloring of the leaves in the background of those shots is (at least possibly) a fringing effect, an aberration possibly related to the bleeding that Misha suggests. I don't know whether or not it would occur with film on overexposure of the adjacent areas this way; it seems to me unlikely, but Alpha would know :-D for sure. In any case it works well within the context of these images, so the reason to understand it is so that you (we) can use it when you (we) want to.