Different designs on different slides?

Can't figure out if I'm just being dense in not being able to figure this out . . . 

I want to use different designs on different slides within a single presentation, but can't figure out how. We're trying to decide on an overall design for our e-learning, so I'd like to have a few different designs within a single module so that the various stake-holders can see different possibilities all in one place (vs. having to go through a few different modules).

However, whenever I click on a standard design, Storyline changes my entire presentation to that design.  I've managed to get a different design on one slide, using a template, but most of the templates aren't really what I'm looking for, and I'd like to be able to  use a variety of designs. is there a way to "unlink" slides so that I can have different background colors and designs on each?