Be careful about painting it darker. 1) the darker units get much warmer inside when in the sun. 2) the outside shell gets much hotter to the touch, to the point of possible skin damage. 3) the added heat may melt the adhesive holding the skin onto the core. "may" is not really "may", so I would not paint a white trailer a darker color.
I lusted for a SilverTrail, until I heard about the above situations.