I also have the ultra white paint. I had a large stone damage the area indicated in my attached picture. About a 4 inch area was repainted at a body shop and blended into the rest of the bumper to avoid re painting any unnecessary areas. They could have blended into the hood but I decided against it. This area is noticeably whiter than the factory paint which has a little more yellow tone in it. 3 stage paints are just hard as light changes the way they look. There are certain lighting conditions where I don't notice and others where it is blatantly different to my eye. The body shop I went to is the best rated in my area and this was the closest they could get it.

That being said, I'm a pretty neurotic person when it comes to details. I have the touch up paint (should be 2 separate ones) and touch up any small chips showing black underneath as I notice them when washing the car. Its actually a pretty good match, not perfect, but still better then the black showing...

 

Congrats on the new ride! Definitely go for the touch up on this one...as the others have said you could get a slight mismatch in color and end up very unhappy..in a few months you'll forget its even there..

 

You can also use Dr. ColorChip. It worked pretty well on Atomic Silver especially on small spots like that. You will need to probably reapply several times to get it all even out.

 

Something that small I would just touch up. You can't repaint the car every little scratch. My paint seems to chip very easily, so I would be repainting every year.

I would avoid a major repaint. While I have had some cars repaired perfectly matched, I also see others with slight hue differences. Many times I also get polishing swurls.