Problem configuring theme-specific parameters, am I doing something wrong?

I decided to start playing around with Hugo this week, and I liked the look of the recently-released redlounge theme. Reading the documentation, it seems there is a banner param that sets the page banner. From what I understand, I can specify this in the markup for a single page as well as globally. Indeed, when I add banner = "/img/my_logo.png" into the post md, it works just fine, so I copied themes/redlounge/archetypes/ into <root>/archetypes and added this line. Didn’t work. Then I attempted to add it to config.toml under [params], which I understand is where theme-specific parameters go. No result there either. Am I doing something wrong, or do I need to submit an issue with the theme designer?

What are you trying to do? Set “banner” globally? Looking at the theme, it doesn’t seem like that’s supported, only .Params.banner which AFAIK comes from individual content):

But, according to the docs, in some cases you'll want to define these in the archetypes so you don't need to keep defining the values. Doesn’t that mean I can define such params in the default archetype?

Ah, I think I’ve figured it out. The single test post I created was done before the archetype was modified, and thus the page wasn’t rebuilt from the template.

Yes exactly, the stuff in the archetype will be the default value for new content. Also see this discussion: