Beagle....do you still believe in the Tooth Fairy, Easter Bunny, and the good will of all mankind? Surely, you cannot be so naive as to believe flying without markings...or false markings makes a bit of difference in the grand scheme of things?
I am sure the Thundering Herds run around in uniform all the time....operational requirements dictate the style and mode of dress, uniform, badges, markings, and flags flown by military units doing operational taskings.
The Oppos do not wear uniforms, badges of rank, unit crests.....and certainly do not give one bit concern to the legalities of war as set forth by the Geneva Accords.
So why would you allow yourself to get your knickers in a twist over unmarked aircraft flying around? Could it be if they cannot get the markings on....they might use improper RT procedures?
You reckon all the space vehicles in the sky are for scientific purposes....including the ones billed as being scientific in nature? Wonder what kinds of pic's the Hubbell sent back when not looking away from Earth? That certainly did not have military markings on it.