Wow... The feelings I get from this piece are a bit overwhelming. On the one hand, the surroundings give me a feeling of dreary monotony and a faint wieght of sadness, kind of wistful and stuck in a rut. I love scenery and locales like that, because despite giving me the feelings listed, I do still tend to get a feeling of comfort from the way those places seem shut off... I can't really explain it, I get the same feeling from deserted and dilapidated structures.
But then on the other hand, the very idea of the paper planes being light enough to follow the wind away from that place and the child's serene expression (and colour) really give me a sense of hope and happiness.
The colour on the child versus the greyscale of the scenery isn't too extreme of a difference, but it's the subtlety in the very fact that there is colour that makes the piece all the more effective.