UBB.threads PHP Forum Software Community Forums Resources and Customizing How Do I? Seperate (forced) Styles for each forum

My board didn't allow users to switch styles before upgrading to 7.6.0. We have separate, unique for each of the forums instead.

I don't remember how I set that up again. Anybody have a clue as to how I can do it? I removed the bit in the footer for changing styles, but now only the default style shows everywhere.