I think for now the best option is to have two component libraries: Theme 1 component library and Theme 2 component library even though they are duplicates of one another. In general, I’m hesitant recommend using the swap library feature for theming because it causes more work on the DS management side. As for your workaround with creating a local override on the color, sure, it’ll then work with swap library but if there’s an update to the main component in the library, it won’t see it and you’re then manually swapping everything again. I think Figma will have more updates in the future specifically for themes, but in the meantime I’d recommend you try out the Themer plugin.