Did you intend for the colors to look this way? If not, they're really unappealing; if so, I don't see why. Furthermore, I'm just not very drawn to the picture.
For me, I like photos where the main subject isn't in the center of a photo - just seems to add a bit more interest when they are more off to one side or the other. Judging by the background landscape, looks like a beautiful place.
The greenish color cast makes this photo very hard to look at. It's awfuly busy and doesn't really tell a story. The countryside looks very pretty, perhaps if you had posed the guy in the bed of the truck with the mountains behind him, or something like that...
Nice shot, looks like a good place to take a coffee break, where is this taken, I get a very "australian" feel from this picture even though I have never been there. Anyway, I still would have liked this shot a whole lot better if it weren´t for the green hue cast and maybe a wider shot with the rest of the truck all in the frame...