Having dynamic themes on a form depending on a value

I’m currently working on a project that will be used by multiple partners, each with their own clients. Each partner has distinct branding guidelines, and we want to create a dynamic theming system that adjusts based on the partner. Specifically, we’d like the theme to change automatically when a user logs into the form, depending on a value such as their email address domain. Our goal is to avoid creating multiple copies of the form for each partner, as that approach would be inefficient and difficult to maintain. What’s the best way to implement this dynamic theming system without resorting to creating separate versions of the form?

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