The white one would be easiest to paint. The grey would be best if you're a smoker or Vaper because of the position of the hole at the front. Cross off the orange one because it'll let too much rain in and looks plain daft. The black one has pink, which is cool if you're a homo, as it gives that little clue without being too obvious. Hmmm - difficult choice.
I think I'd get the white one because you could use it as a snow shovel in the winter.