As Syrus said, the Colonials have their very-fitting Zephyr and the "mixing of the lines" with the IMG has stopped for a few years now. Your model is ok, but I'm not a fan of the ridges on its back, nor the obvious horns and spikes for the distinctive Colonial feel.
While discussing the subject of lines, the Colonial one doesn't really need work. At least to me the Nyx, Thanatos, Zephyr are some of the best models in the game and the rest of them are at the very least suitable. I believe the Atlas is getting a slight update to its internal storage compartments (a solid block instead of the 'gas spheres') but other than that, they don't need any work. Hard-headed or otherwise, there are other lines that would do much better with some work.
Golly is also right, correct one would be the logo here, perhaps red for the Military (yellow is civilian, white/grey is Intelligence).
