The black smoke is from the burning of the carbon, not the atomization. The efflux on the turbines is just hot enough too cause it to vaporize, and it is not burning. Try holding a torch to the tail end of turbine with the "white smoke" coming from it and see what will happen, especially if you can increase the oxygen content just a little bit. The vaporized material should ignite and will not burn too effeciently. There should be plenty of black smoke.
I may be totally wrong here, but I am not sure how you are gonna get a "balck, greasy" smoke from just atomization.
Those pics of the B52s and B47s show an engine where a huge amount of fuel is being injested and burned ineffeciently. In that case there is not enough oxygen there for a complete burn and you get the large amount of carbon. Introduce a higher oxygen level in the engine and you would not get as much smoke. there is a fine balance here in the combustion of these hydrocarbons. I think in our case where we are atomizing the hydrocarbons, we could get smoke by introducing a small amount of oxygen and then igniting the mixture.