At the time of writing, you can choose one of three adminpanel design themes:
You can choose one of the themes when creating the panel, but then, at any time, you can change the theme in settings:
A few disclaimers:
As we use the theme "as is", we are not responsible for any front-end issues in their code, check their Github issues and documentation.
We are using only the minimum amount of elements from those themes - only overall design, forms, tables, so things needed for adminpanel. If you want to use more elements from the original theme, read the documentation on their page.
We are using the exact version (vX.Y.Z) of the theme that is hard-coded in our generator, so if they release some upgrades, it's not automatically reflected on our side. We even had incident with CoreUI that moved their CDN to a newer v3 version, breaking the panels for our customers. We are trying to monitor such possible issues and fix them as quickly as possible.
Within our license boundaries, we are using Free version of all themes, including CoreUI. Unfortunately, we don't have any tutorial for the upgrade to Pro. Please check their documentation.
It's very individual. From the time of working with Bootstrap-based themes, we found out that only on the surfaces they are similar, deep down under the hood many elements are structured and named differently, so there's no "simple change" of the theme, you need to do it manually based on the docs of current and your desired theme.
That said, all themes are based on Bootstrap, so naming of classes should remain almost the same, that should help you in the process.
In older version of QuickAdminPanel, in 2017, we had released a tutorial: Changing QuickAdminPanel theme: from AdminLTE to Gentelella. It is now outdated, but it should give you an overall impression, on what work is included in changing the Bootstrap theme.
We had a few ideas for new themes, like Material Design, but after a while we realized that it takes us a lot of time to adopt (and support!) the new theme, so we better spend those weeks working on the back-end functionality of the Laravel generator, which is our overall mission.
Maybe in the future we will focus more on the design and front-end side of things, if we feel that customers demand this.