Some ideas on what to do for final paint. The belly can be painted non white if it is kept to a light color. That is a nice way to add a little color to the often bland composites overall white. My top pick (at the moment) is to use an Orange-Yellow color (nice and Bright) for the primary color and trim it with shades of Purple. The Grey with Purple trim is a bit more like what you see on a lot of the factory built aircraft and would make a nice choice but I just like the appeal of brighter colors.