Which is not indicative of what it looked like in the 1960s, because it was after a prior restoration done without accurate reference.
We do have original Paramount promotional stills of the 11' Enterprise
for the regular series and one was posted here
In post # 75 I provided a link to a close up picture of the starboard underside of the saucer, taken by Phil Broad after the second Smithsonian upgrade (i.e. no more duct tape on the port side of the model). In this shot you can still see the very tiny pencil lines you can also find on the promotional still. No paint job touched this section of the ship.
Additionally, the Ed Miarecki photographs show the upper side of the saucer in its original condition. Again, tiny pencil lines and all the specialists agree that this is the original, unpainted and untainted version.
Admittedly, there are hints that areas of the ship had to be reconstructed and repainted, but this doesn't necessary imply that the entire
engineering hull or the nacelles were repainted prior to the restoration effort.