In the foreground are three groups of figures, from the left, are the three Horatii brothers standing close next to one another in power poses, their legs are wide apart, and their feet are planted on the tiled floor.
The color scheme is subdued in Oath of the Horatii, depicting somewhat muted reds, blues, mustardy-brown/beige, off whites, but also deeper shades of blue and green, and golds and silver for the swords and helmets.
There is implied texture, notably in the various softer folds of the clothing, which is contrasted with the hardness of the interior space’s brick walls, columns and arches, and tiled floor.
The straight lines are evident in the men’s upright and often-described “rigid” postures, the diagonal lines created from the legs, and the straight vertical lines implied by the swords, spears, and importantly the three vertical columns in the background.
The work follows naturalistic forms, notably in the figures, for example, the men appear athletic and muscular, and the women appear more curvaceous. The natural forms are contrasted by the geometric shapes of the architecture.
The compositional space is composed of the foreground, where all the primary figures are placed, the narrative takes place and the background is depicted as an empty dark space, which further places emphasis on the foreground.