in the middle-ground is the river and the grasslands in bright hues of blue and green. the background, which is cut off by the horizon line of the darker blue river, is a pale blue sky highlighted with white and gray clouds. this compositional form is applied here by the crowded left and right sides bracketed by hills, which pushes the viewer's eye into the open space in the middle and reinforces that the men in the boat are the main focus of the painting.