Branded CSS; user customized styles

Hello, our team needs to allow clients to brand their Ionic app by customizing a few colors and images. We also need to show the user the result of their branding changes in “real time” (not necessarily real time but, reasonably quickly, show them the result of their changes in the app).

The current idea is to send a request to our server to update their branded SCSS variables, have a process recompile the app, grab the resulting main.css, and then finally send that one file back to the client for them to preview.

Once they’re satisfied and they decide to keep their changes, we use the app’s service worker to allow other app installs for that client to update themselves with the latest branded css file.

Does that make sense? Is there a smoother/simpler/faster way to do this? We want to leverage the power of compiling to CSS and make sure our code stays as clean as possible (no inline styles, etc).

Does anyone know if there’s a way to only compile the CSS for the app?