It seems like black would be a bad exterior color choice for heat purposes. Also, if I were to buy one of these, I would want it in a plain white container so as to not advertise that I have hundreds of thousands of dollars worth of computers inside of a highly mobile unit.
I'm sure that the stuff on Sun's website is just the "omg cool" marketing version; the real version probably has a less "awesome" color scheme. But you do bring up a good question... where do you store these containers? Do you just rent a warehouse and have them delivered?
You put them on a train that doesn't stop moving around the country to hide your whereabouts as you use your servers to facilitate your data-hungry conspiracy needs, of course.