EDIT: I had the opportunity to sit down with an medical student last night and figure out how arms work! It looks like in the places where only the upper arm is shown:
-Green is the biceps
-Yellow is the triceps
-Blue is the latissimus dorsi
-Red is the deltoid
In the images showing the back, everything is the same but yellow marks the trapezius. Green marks a whole complex of muscles under the scapula.
In the images showing the whole arm:
-Green is the biceps
-Yellow is the triceps
-Blue is the brachioradialis
-Red marks the ulna (the bone that goes from the ball of your elbow to the outside of your wrist)
I thought this might be helpful for anyone learning how these muscles fit together! Learning that has been extremely useful for me!