Sorry I'm a bit of a noob, I don't get this " by setting an additional color." I must be missing something.
Currently for the level I have
world.setAmbientLight(250, 250, 250);
For the models I want something like
world.setAmbientLight(20, 20, 20);
sun = new Light(world);
sun.setIntensity(250, 250, 250);
But they are both in the same world!