Golden comets have dominant white so they are going to have a tail that contains white feathers and or white in the wings.
Production red are a taller bird with an angular shaped breast like a New Hampshire. They can be a dark red but are not shaped like a RIR.
New hampshire are lighter colored and the color will vary over different parts of the body. They stand taller than a RIR.
Rhode island red should be a brick shaped bird. Like a head, neck and legs glued to a big rectangular brick. They should be the same color (except the black in the wings and tail) over the body of the bird.