I went to the Apple Store today to see all the colors as well.
At some point in the 10 minutes I was there, however, the sun went behind the clouds, and then the Midnight appeared to be just a very dark gray, which I, personally, found much less appealing. At this point, the lighting in the room was probably closer (though still much brighter) than that in most people's homes, so I suspect that this grayer appearance is what most people are going to see most of the time.
A Starlight model was right next to the Midnight one, and I'm now very glad I finally settled on Starlight last week. To my eye, it is a very warm silver. It looks understated, classy and, dare I say, expensive.