Advanced apologies if this is addressed something but the long road to Discourse’s current dark mode support makes searching for this difficult. 
Is there support for declaring light and dark colors for category boxes/bars, etc? AFIAK since the category color is declared on the category edit page there’s only one color available. Thanks!
We don’t have the option to at the moment… it could be done with CSS, but it would likely be fiddly and require some !important styles because we apply the colors inline in the HTML.
As a side note, we should probably look into remove those inline styles and use CSS custom properties for the category colors instead…
I’m going to change the category on this to #feature because it seems like a reasonable request to me.
