Well, the images found below, taken by yous truly, should help. You will see him in both natual light and indoor lighting. I can attest that the grey plastic on God Bomber's chest appears to same to me as the grey plastic on Magnus Prime's thighs. Magnus prime's grey plastic for the trailer is far more grey/silver than the plastic found on Hasbro's Leader Power Master Optimus Prime which is more tan. This works well with the silver/grey paint founs on the boots formed from God Bomber. Hopefully this answers a few questions.
The combiner ports arent tucked in since doing so results in the red pieces forcing the trailer panels to become undone.