Pahlava Government

I'm playing as Pahlava, and as I conquer Seleukid cities I destroy their government buildings to establish my own. But I notice that before I destroy their government buildings I have a Pahlava government option with a crown in the icon, and afterwards I can't get it back, only lvl 4 governments of my own. I know it's awfully vague, but can anyone tell me if I'm effing up?

That's actually a colony building... It resembles a government building, but I assure you it is not.

which one?

Pahlava government-style icon with a large yellow crown. That is a colony building. Please refer to the building tress, provided here.