That said, I understand why this feels “unexpected”, and it’s something that I’ve considered off and on for some time for this reason. I took another dive into the discourse theming system and there is now a more straightforward way to seperate out the “color schemes” of different themes for the discourse client. I’ve tweaked the handling of wizard themes to use the color scheme associated with different themes selected for the discourse client as a base. Happily, a simple update.
This means that if a user selects a different theme in their user preferences, the color scheme associated with that theme (and nothing else in the theme) will be applied to the wizard via the :root variables. I think this is the expected outcome you’re pointing at in this report. And this will probably align with others’ expectations.