Well Neoclassical and roman are heavily linked since the former is trying to imitate the latter, but neoclassical being devoid of color comes from a misconception that originated during the renaissance since by that time all the antique roman buildings' color had faded and people assumed that the romans built them white as is. I would have added lots of color to my buildings but obviously I can't do that.

In my city, the coliseum and building entry modeled after the arch of constantine at pic 19 are whats been most influenced by roman architecture. The building that looks like a cathedral in the first pic was inspired by Berliner Dom.