To add metal for a two tone, the top has to overlap the bottom portion so water will not get in.
Myself, personally, I like the looks of the barn the way it is. I think by the time you get your grass grown, and maybe a little landscaping, you won't notice how tall the walls are. If anything, if you want to break up the expanse of the brown, just add a porch on the front over the entrance door over to the corner. Then your eye will be drawn to the porch and not the sidewall.