Yes, they have pretty paint on most rebuilt starter motors. Some vendors do not install new brushes, bearings, etc., because they only need the starter to make it beyond the warranty period. You said your starter motor was original, so you also know they should last a very long time.
That's why I urged you to:
Originally Posted by simplyconnected
... take the internals out of both, then clean up and use the old body with the best parts. It looks harder than it really is....
If the new armature's commutator looks better, use it. I offered pictures of the whole setup but hey, do what you like. I realize you bought a new starter motor but just to make sure, loosen the inspection band and look inside. Only one bolt holds it on. - Dave