You could develop the same appearance just with a bad bruise and as the blood migrates there will be different patterns and colors as the blood material is processed by your soft tissue.
As is usually the case in these "remote advice" situations, where i might be of help is to let you know what are some warning signs to look for that would mean you must get your arm checked out. So, here are a couple:
1) are you having any significant numbness
in your hand, or decreased ability to move your fingers, either because you simply cannot move them as well or because every move that stretches a muscle group makes it hurt a lot? You can also move your fingers with your other hand to see if that hurts a lot too. If so, you could have so much swelling that your soft tissues (muscles, nerves) are being compromised. You should definitely have your forearm evaluated.
2) are you having significant pain in your forearm with rotation of the arm (i.e. Turning your palm facing up and then down)? If so, you might have a fracture
. Of course, obvious fractures with notable displacement would have sent you to the emergency room already; what sometimes is missed would be the fracture that results in a crack but not significant displacement, therefore the arm still looks normally aligned and is even quite comfortable at rest, but is painful with any movement or rotation. If at ten days after injury you are still having this kind of symptom, you should also have your arm checked out by a physician, who will most likely order an x-ray series. If there is a hairline crack and you are not aware of it to protect it, the fracture may displace with trivial action or movement, complicating your treatment.
After all of the above scary scenarios, i hope in reality your arm is already much better by now, after ten days!
jim hsu, md