So far I've only used Burnt Umber for the overall washes.
I picked up some other colors to try to do some streaks, two shades of green, another shade of brown, white, med blue, yellow and a dark red. I've never done the dot/streak method before, so I'm going to start off very conservatively. My focus will be to put down some redish/brown streaks to simulate rust streaking down from the bolts on the superstructure. That will hopefully give me a good idea on the technique, then I may do some other random streaks with the other colors.