Ink wash to add depth to the plastic tone and gorgeously detailed sculpt, then some silver and gold detailing to make him look a bit more like an ornate Prime. I focused the gold on the shuttle mode, and the silver on the train mode. Also painted "Infinitus" to look more like Sentinel in Megatron: Origin, since the sculpt is clearly designed after that form.
Wow. As great as the overall work is... I'm most impressed by that little Headmaster. All that detail... and it's completely lost because the stock version has virtually no paint to it.
Haha, thank you! I normally paint Gundam models, so painting small figures is something I love doing. It's really a shame that the retail version has no effort at all put into showing off how dedicated the sculptors are!