Throughout the film, the new recruits have wounds caused by the experiment, these are shown on the left hand side of their necks, but during the experiment, the machine injects a needle type object, into the back of their necks.
The major in the movie has Lt. Col. rank on his cover (hat) and on both sides of is uniform.
No one in the Army wears solid black uniforms. They also never wear ribbons, pins, or shinny rank on the uniforms. They would also never point an M-16 in the face of another soldier.